Since the 1993 National Research Council (NRC) report on child abuse and neglect was issued, dramatic advances have been made in understanding the causes and consequences of child abuse and neglect, including advances in the neural, genomic, behavioral, psychologic, and social sciences. These advances have begun to inform the scientific literature, offering new insights into the neural and biological processes associated with child abuse and neglect and in some cases, shedding light on the mechanisms that mediate the behavioral sequelae that characterize children who have been abused and neglected. Research also has expanded understanding of the physical and behavioral health, academic, and economic consequences of child abuse and neglect. Knowledge of sensitive periods—the idea that for those aspects of brain development that are dependent on experience, there are stages in which the normal course of development is more susceptible to disruption from experiential perturbations—also has increased exponentially. In addition, research has begun to explore differences in individual susceptibility to the adverse outcomes associated with child abuse and neglect and to uncover the factors that protect some children from the deleterious consequences explored throughout this chapter. An important message is that factors relating to the individual child and to the familial and social contexts in which the child lives, as well as the severity, chronicity, and timing of abuse and neglect experiences, all conspire to impact, to varying degrees, the neural, biological, and behavioral sequelae of abuse and neglect. Show
This chapter begins by exploring background topics that are important to an understanding of research on the consequences of child abuse and neglect, including an ecological framework and methodological attributes of studies in this field. Next is a review of the research surrounding specific outcomes across the neurobiological, cognitive, psychosocial, behavioral, and health domains, many of which can be seen in childhood, adolescence, and adulthood. The chapter then examines outcomes that are specific to adolescence and adulthood, reviews factors that contribute to individual differences in outcomes, and considers the economic burden of child abuse and neglect. The final section presents conclusions. CASCADING CONSEQUENCESNewborns are almost fully dependent upon parents to help them regulate physiology and behavior. Under optimal conditions, parents buffer young children from stress and serve as “co-regulators” of behavior and physiology (Hertsgaard et al., 1995; Hofer, 1994, 2006). Over time, children raised by such parents gradually assume these regulatory capacities. They typically enter school well regulated behaviorally, emotionally, and physiologically; thus, being prepared for the tasks of learning to read, write, and interact with peers. For some children, parents cannot fill these roles as buffer and co-regulator effectively. When children have caregivers who cannot buffer them from stress or who cannot serve as co-regulators, they are vulnerable to the vicissitudes of a challenging environment. Although children can cope effectively with mild or moderate stress when supported by a caregiver, conditions that exceed their capacities to cope adaptively often result in problematic short- or long-term consequences. Studies conducted with some nonhuman primate species and rodents have shown that the young are dependent on the parent for help in regulating behavior and physiology (Moriceau et al., 2010). Thus, young infants are dependent on parents fulfilling the functions of carrying, holding, and feeding. The period of physical immaturity and dependence lasts an extended time in humans. Even beyond the point at which young children are physically dependent, they remain psychologically dependent throughout childhood and adolescence. Thus, inadequate or abusive care can have considerable consequences in terms of children's health and social, psychological, cognitive, and brain development. Children who have experienced abuse and neglect are therefore at increased risk for a number of problematic developmental, health, and mental health outcomes, including learning problems (e.g., problems with inattention and deficits in executive functions), problems relating to peers (e.g., peer rejection), internalizing symptoms (e.g., depression, anxiety), externalizing symptoms (e.g., oppositional defiant disorder, conduct disorder, aggression), and posttraumatic stress disorder (PTSD). As adults, these children continue to show increased risk for psychiatric disorders, substance use, serious medical illnesses, and lower economic productivity. This chapter highlights research supporting the association between these outcomes, among others, and experiences of child abuse and neglect. The potential dramatic and pervasive consequences of child abuse and neglect underscore the need for research to illuminate the myriad pathways by which these ill effects manifest in order to guide treatment and intervention efforts. However, it is important to note at the outset that not all abused and neglected children experience problematic outcomes. As discussed in the section on individual differences later in this chapter, a body of research is devoted to uncovering the factors that distinguish children who do not experience problematic outcomes despite facing significant adversity in the form of abuse or neglect. Further, as discussed in Chapter 6, the past two decades have seen substantial growth in proven models for treatment of the consequences of child abuse and neglect, indicating that these effects are potentially reversible and that there is opportunity to intervene throughout the life course. BACKGROUNDSeveral key concepts need to be considered in attempting to understand potential pathways that lead from abuse and neglect to the various consequences discussed in this chapter and the context in which those consequences manifest. First, positive and negative influences found among individual child characteristics, within the family environment, and in the child's broader social context all interact to predict outcomes related to child abuse and neglect. Second, child abuse and neglect occur in the context of a child's brain development, and their potential effects on developing brain structures can help explain the onset of certain negative outcomes. Finally, abused and neglected children often are exposed to multiple stressors in addition to experiences of abuse and neglect, and potential consequences may manifest at different points in a child's development. Therefore, the most rigorous research on this topic attempts to account for the many factors that may be confounded with abuse or neglect. Ecological FrameworkSince 1993, transactional-bioecological or ecological models have guided attempts to conceptualize the relative contributions of risk and protective factors to children's developmental outcomes, particularly in relation to child abuse and neglect (Belsky, 1993; Cicchetti and Lynch, 1993; Cicchetti and Toth, 1998). Versions of this approach consider the development of the child in the context of the broader social environment in which he or she functions, within the context of a family; in turn, children and families are embedded in a larger social system that includes communities, neighborhoods, and cultures. The assumption underlying these models is that behavior is complex, and development is multiply determined by characteristics of the individual, parents and family, and neighborhood and/or community and their interactions. In examining the role of contextual factors in the onset of consequences due to child abuse and neglect, Cicchetti and Lynch's (1993) ecological/transactional model is particularly useful because it successfully incorporates multiple etiological frameworks (Lynch and Cicchetti, 1998). This model is based on Belsky's (1980, 1993) ecological model and Cicchetti and Rizley's (1981) transactional model. It expands on these models by highlighting the nature of interaction among risk factors and the ecology in which child maltreatment occurs. The ecological/transactional model describes four interrelated, mutually embedded categories that contribute to abuse and neglect and the potential associated consequences:
The model is based on the fact that a child's multiple ecologies influence one another, affecting the child's development. Thus, the combined influence of the individual, family, community, and larger culture affect the child's developmental outcomes. Parent, child, and environmental characteristics combine to shape the probabilistic course of the development of abused and neglected children. At higher, more distal levels of the ecology, risk factors increase the likelihood of child maltreatment. These environmental systems also influence what takes place at more proximal ecological levels, such as when risk and protective factors determine the presence or absence of maltreatment within the family environment. Overall, concurrent risk factors at the various ecological levels (e.g., cultural sanction of violence, community violence, low socioeconomic status, loss of job, divorce, parental substance abuse, maladaptation, and/or child psychopathology) act to increase or decrease the likelihood that abuse will occur. The manner in which children handle the challenges associated with maltreatment is seen in their own ontogenic development, which shapes their ultimate adaptation or maladaptation. Although the overall pattern is that risk factors outweigh protective factors, there are infinite permutations of these risk variables across and within each level of the ecology, providing multiple pathways to the sequelae of child abuse and neglect. Types of EvidenceMany studies of the consequences of abuse and neglect have been conducted with methodologies ranging from prospective to retrospective designs, from observational measures to self-report, and from experimental to case-controlled designs to no-control designs. The strongest conclusions could be reached with experimental designs whereby children would be randomly assigned to different abusive or neglectful experiences; however, this is obviously neither desirable nor possible. Nonhuman studies involving primates and other species have allowed experimental assessment of different rearing conditions that may parallel human conditions of neglect and abuse (e.g., Sanchez, 2006; Suomi, 1997). One salient human study involved random assignment of children abandoned to institutions to high-quality foster care (a randomized controlled trial of foster care as an alternative to institutional care) (Nelson, 2007). In this prospective, longitudinal study, known as the Bucharest Early Intervention Project, 136 children abandoned at or around the time of birth and then placed in state-run institutions were extensively studied when they ranged in age from 6 to 31 months (mean age = 21 months), as was a sample of 72 never-institutionalized children who lived with their families in the greater Bucharest community. Following the baseline assessment, half of the institutionalized children were randomly assigned to a high-quality foster care program that the investigators created, financed, and maintained, and half were randomly assigned to remain in care as usual (institutional care). These children were followed extensively through age 12 (for discussion, see Fox et al., 2013; Nelson et al., 2007a,b; Zeanah et al., 2003). Although at first glance it may not be obvious why the study of children reared in institutions is relevant to a report on child abuse and neglect, institutional care, which affects as many as 8 million children around the world, can involve an extreme and specific form of neglect—broad-spectrum psychosocial deprivation. Therefore, neglectful institutional care settings can serve as a model system for understanding the effects of neglect on brain development. The neglect experienced by children in such settings should not serve as a proxy for the type of neglect experienced by noninstitutionalized children in the United States, who are more likely to experience neglect in such domains as food, shelter, clothing, or medical care rather than broad-spectrum psychosocial deprivation. Nevertheless, this study can provide important insight into the effects of neglect on behavioral and neurological development because of its randomized, controlled, and longitudinal nature. The discussion in this chapter necessarily relies primarily (although not exclusively) on the strongest nonexperimental studies conducted. These studies involve longitudinal prospective designs, which assess child abuse and neglect objectively at the time of occurrence and assess outcomes longitudinally. A good example is the study of Widom and colleagues (1999), which followed a large cohort of abused and neglected children and a matched comparison sample from childhood into adulthood. Other examples include the studies of Johnson and colleagues (1999, 2000), Noll and colleagues (2007), and Jonson-Reidz and colleagues (2012). Retrospective designs that ask participants to recall whether abuse and neglect were experienced are more troublesome because recall of child abuse and neglect can be affected by a variety of factors and open to a number of potential biases (Briere, 1992; Offer et al., 2000; Ross, 1989; Widom, 1988). Results of studies based on treatment samples of adults who experienced maltreatment as children may be potentially biased because not all victims of child abuse and neglect seek treatment as adults, and because people who do seek treatment may have higher rates of problems than people who do not seek treatment (Widom et al., 2007a). When participants are asked to report on conditions such as current depression and previous history of child abuse and neglect, the added problem of shared method variance arises. On the other hand, use of official records raises the problem of underreporting (Gilbert et al., 2009a). The federal government has supported an effort, launched since the 1993 NRC report was issued—the National Survey of Child and Adolescent Well-Being (NSCAW)—to expand understanding of the consequences of child abuse and neglect. This study includes use of multiple data sources and record reviews, as well as interviews with children and youth who have experienced child abuse and neglect, their caretakers, and child welfare workers. Several of its findings are discussed in Chapter 5. This chapter contains an extensive review of the more recent biologically based studies of child abuse and neglect because of the important advances that have been made in this area. To the extent possible, the discussion relies on findings from studies characterized by the greatest methodological rigor. Despite recent methodological advances, researchers face many challenges in attempting to understand the short- and long-term consequences of the various types of child abuse and neglect (e.g., physical abuse, sexual abuse, neglect from caregivers) for child functioning and development. One of those challenges is teasing apart the impact of child abuse and neglect from that of other co-occurring factors. For example, children involved with child protective services because of neglect or abuse often face a number of overlapping and concurrent risk factors, including poverty, prenatal substance exposure, and parent psychopathology, among others (Dubowitz et al., 1987; Lyons et al., 2005; McCurdy, 2005). These concurrent risk factors can make it particularly difficult to draw causal inferences about the specific consequences of abuse and neglect for children's functioning, but need to be disentangled from the specific effects of abuse and neglect (Widom et al., 2007a). Controlling for other relevant variables becomes vital, since failure to take such family variables into account may result in reporting spurious relationships (Widom et al., 2007a). Some studies consider and covary other risk factors, and some do not. Considering the course of abuse and neglect may also be particularly important, as Jonson-Reid and colleagues (2012) found that the number of child abuse and neglect reports powerfully predicted adverse outcomes across a range of domains.
NEUROBIOLOGICAL OUTCOMESAn adequate caregiver is needed to support developing brain architecture and the developing ability to regulate behavior, emotions, and physiology for young children. When children experience abuse or neglect, such development can be compromised. The effects of abuse and neglect are seen especially in brain regions that are dependent on environmental input for optimal development, and on aspects of functioning especially susceptible to environmental input. Early in development, infants are completely reliant on input from their caregivers for help in regulating arousal, neuroendocrine functioning, temperature, and other basic functions. With time and with successful experiences in co-regulation, children increasingly take over these functions themselves. Abuse and neglect represent the absence of adequate input (as in the case of neglect) or the presence of threatening input (as in the case of abuse), either of which can compromise development. The following sections present a review of evidence with respect to key neurobiological systems that are altered as a result of abuse and neglect early in life: the hypothalamic-pituitary-adrenal (HPA) axis of the stress response system; the amygdala, involved in emotion processing and emotion regulation; the hippocampus, involved in learning and memory; the corpus callosum, involved in integrating functions between hemispheres; and the prefrontal cortex, involved in higher-order cognitive functions. The discussion begins, however, with a brief overview of brain development. Overview of Neurobiological DevelopmentThe Construction of the BrainBrain development begins just a few weeks after conception, starting with the construction of the neural tube. This is followed by the generation of different classes of brain cells—neurons and glia. Once formed, these immature neurons begin their migratory phase (generally away from the ventricular zone, which is their point of origin) to build the cerebral cortex. Much of cell migration is completed by the end of the second trimester of pregnancy, eventually leading to the construction of the six-layered cerebral cortex. After these immature cells have migrated to their target destination, they can differentiate; that is, they develop cell bodies and processes (axons and dendrites). Once processes have been formed, synapses begin to form; synapses are the connections between neurons that allow for the transmission of signals across the synaptic cleft, which is the small space that exists between two adjacent brain cells, generally between a dendrite and an axon. The synapse permits one neuron to communicate with another, and eventually, entire circuits are built, followed by neural networks (i.e., organized units). Finally, some axons in the brain develop a coating called myelin that speeds the flow of information along the length of the axon. Sensory and motor pathways begin to myelinate during the last trimester of pregnancy, whereas association areas of the brain, particularly the prefrontal cortex, continue to myelinate through the second decade of life. Neural elements (e.g., axons) that are coated with myelin are referred to as white matter, whereas most of the rest of the brain is referred to as grey matter. Many aspects of brain development (particularly those that occur before birth) fall under genetic control (although some are affected by experience—prenatal exposure to neurotoxins such as alcohol being but one example). After birth, however, much of brain development becomes dependent on experience. For example, although the generation of synapses—which are massively overproduced early in development—is largely under genetic control, the pruning of synapses—which occurs primarily after birth—is largely under experiential control. Thus the prefrontal cortex of the 1-year-old child has many more synapses than the adult brain, but over the next one to two decades, these synapses are pruned back to adult numbers, based largely on experience (Nelson et al., 2011). Neural Plasticity and Sensitive PeriodsMany aspects of brain development depend on experiences occurring during particular time periods, often the first few years of life. These so-called sensitive or critical periods represent vital inflection points in the course of development, such that if specific experiences fail to occur within some narrow window of time (or the wrong experiences occur), development can go awry. This leads to the concept that plasticity “cuts both ways,” meaning that if the child is exposed to good experiences, the brain benefits, but if the child is exposed to bad experiences or inadequate input, the brain may suffer (Nelson et al., 2011). Prenatally, an example of a bad experience is exposure to neurotoxins such as alcohol or drugs of abuse. An example of a good experience is access to good nutrition, including the many micronutrients that facilitate brain development (e.g., iron, zinc). Postnatally, the topic of this report represents examples of bad experience (i.e., abuse and neglect). Conversely, examples of good experiences include providing a child with consistent, sensitive caregiving; a nurturing home in general; and adequate stimulation. The Time Course of DevelopmentIn general, most sensory systems develop early in life; thus the ability to see and to discriminate and recognize faces and speech sounds come on line in the first months and years of life, based on appropriate experiences occurring during that time window (e.g., exposure to faces, to speech). This is not surprising given how vitally important these functions are to subsequent development (e.g., language is not learned until children can discriminate the basic units of sound, such as one consonant from another). Critical to the discussion in this chapter, however, is that the functions subserved by some other regions of the brain, most notably the prefrontal cortex—executive control, planning, cognitive flexibility, emotion regulation—have a much more protracted course of development for the simple reason that both synaptogenesis and myelination of these cortical regions do not mature until mid- to late adolescence, perhaps even a bit later. As a result, the sensitive period for prefrontal cortical functions may be far more prolonged than is the case for sensory functions, extending well into the adolescent period. One example of the differential time course of different brain regions, and perhaps their corresponding sensitive periods, is illustrated in Figure 4-1. FIGURE 4-1The time course of key aspects of brain development. SOURCE: Thompson and Nelson, 2001 (reprinted with the permission of American Psychologist). These concepts are important to the study of the neurobiological toll of early childhood abuse and neglect because children who experience considerable adversity early in life may be exposed to environments/experiences that the species has not come to expect (such as abusive caregivers) or worse, environments that are largely lacking in key experiences (i.e., neglect). In both cases, when the expectable environment is violated by either gross alterations in the type of care received or a complete lack of care, subsequent development can be seriously derailed. Hypothalamic-Pituitary-Adrenocortial (HPA) Axis and Biological RegulationThere is strong evidence across species that the HPA axis is affected by experiences of early childhood abuse and neglect (e.g., Bruce et al., 2009; Gunnar and Vazquez, 2001; Levine et al., 1993; Shonkoff et al., 2012). Glucocorticoids (cortisol in humans, corticosterone in rodents) are steroid hormones produced as an end product of the HPA system. The HPA axis serves two orthogonal functions: mounting a stress response and maintaining a diurnal rhythm. A cascade of events is designed to promote survival behavior by directing energy to processes that are critical to immediate survival (e.g., metabolism of glucose) and away from processes that are less critical to immediate survival, such as immune functioning, growth, digestion, and reproduction (Gunnar and Cheatham, 2003). Glucocorticoids also serve an important role in maintaining circadian patterns of daily activity, such as waking up, sleeping, and energy regulation (Gunnar and Cheatham, 2003). Diurnal species, including humans, have a diurnal pattern of cortisol production that enhances the likelihood of being awake at the same time in the day. In humans, diurnal cortisol levels peak about 30 minutes after waking up, decrease sharply by mid-morning, and continue to decrease gradually until bedtime (Gunnar and Donzella, 2002). The higher morning values of cortisol reflect greater metabolism of glucose early in the day, providing energy for the day's activities. The HPA axis is highly sensitive to the effects of early experiences. Diurnal effects typically have been examined as wake-up values and bedtime values because those time points allow assessments of change from nearly the highest reliable waking time point (with 30 minutes post wake-up being the highest) to the lowest waking time point. Daytime values are affected by a number of factors, such as exercise, naps, and travel to work (Larson et al., 1991; Watamura et al., 2002). The most consistent findings involve flatter, more blunted patterns of diurnal regulation among abused or neglected children relative to low-risk children (Bernard et al., 2010; Bruce et al., 2009; Dozier et al., 2006; Fisher et al., 2007; Gunnar and Vazquez, 2001). Similar flattened diurnal rhythms have been found in institutionalized children (Bruce et al., 2000; Carlson and Earls, 1997). Flattened diurnal cortisol patterns may reflect down-regulation of HPA axis activity following earlier hyperactivation (Carpenter et al., 2009; Fries et al., 2005). Cicchetti and colleagues (Cicchetti and Rogosch, 2001a,b) examined changes across the day among abused and neglected children attending summer camp. The time points included when children first arrived at camp (at about 9 AM) and before they left camp for the day (at about 4 PM), likely tapping diurnal change within a challenging environment. The authors report complex findings regarding cortisol in this setting. Differences were found in some studies related to subtype and/or psychopathology and/or aggression (Cicchetti and Rogosch, 2001b; Murray-Close et al., 2008). Animal models have been used to study experimentally the effects of neglect and abuse on HPA functioning (e.g., Levine et al., 1993). Experiences of abuse or neglect, depending on age of pup/infant, duration, chronicity, and subsequent response of dam/mother differentially affect short- and long-term effects on the HPA axis (Sanchez, 2006). Under naturally occurring conditions (about 10 percent of rhesus monkeys abuse their infants), a 1-year-old rhesus monkey that was abused (primarily in the first month of life) showed higher cortisol levels under basal and stress conditions than a 1-year-old that had not been abused. These effects were not seen at older ages. (The age translation from rhesus to human is about 1 to 4, so a 1-year-old rhesus is developmentally similar to about a 4-year-old human child.) In other studies that have manipulated rearing conditions (such as isolation rearing), differences between conditions of abuse or neglect have been inconsistent. In some studies, higher cortisol values were observed in basal and/or stress conditions; in some, lower basal and/or stress conditions; and in some, no differences between the monkeys that had undergone deprivation and those that had not (Champoux et al., 1989; Clarke, 1993; Higley et al., 1992; Shannon et al., 1998). Disrupted HPA axis regulation may have negative effects on a number of other biological systems. High levels of circulating cortisol resulting from early life stress may cause damage to developing brain regions (Teicher et al., 2003; Twardosz and Lutzker, 2010). Several brain regions, including limbic regions such as the amygdala and hippocampus and prefrontal regions, may be particularly susceptible to the effects of high levels of circulating cortisol because of the high number of glucocorticoid receptors in these areas (Brake et al., 2000; Schatzberg and Lindley, 2008; Wellman, 2001). High levels of circulating cortisol may affect telomere length as well. Telomeres are the repeated sequences of DNA that cap the ends of chromosomes. Telomeres shorten each time cells divide, a process generally associated with aging, but also with stress (Epel et al., 2004). If telomeres become too short, the cell may become senescent (grow old) or may become malfunctional, for example, triggering inflammation or tumor development. Children who have been exposed to neglect show shortened telomeres (Asok et al., 2013; Drury et al., 2011). Drury and colleagues (2011) found shorter telomeres among children in institutional care. Similarly, Asok and colleagues (2013) found that children living in highly challenging environments showed shorter telomeres than comparison children, but that mothers could buffer children from the environment challenge. When mothers of neglected children were sensitive to challenging environments, their children's telomeres were as long as those of low-risk children, but when mothers were insensitive, children's telomeres were shorter. Clearly, then, sensitive caregiving serves as a protective factor even under difficult conditions of adversity. There is as yet no compelling empirical evidence among humans that high levels of cortisol result from abuse or neglect and persist long enough to affect brain development adversely, leaving these arguments speculative. Nonetheless, the evidence is compelling that the HPA axis is perturbed in many cases, and perturbations are associated with a range of health and mental health problems (McEwen, 1998; Yehuda et al., 2002). Studies (e.g., McGowan et al., 2008, 2009, 2011; Meaney and Szyf, 2005; Weaver et al., 2004) have found that the effects of abuse on the stress response are mediated by epigenetic programming of glucocorticoid receptor expression. Differential methylation of the glucocorticoid receptor gene promoter in the hippocampus was found to be associated with different rearing conditions in rodents, and was reversed by changes in caregiving conditions (McGowan et al., 2008). Paralleling these findings among rodents are nonexperimental findings among humans examined in postmortem analyses (McGowan et al., 2009; Szyf and Bick, 2013). Adult suicide victims who had experienced abuse as children differed in glucocorticoid receptor mRNA from adult suicide victims who had not experienced abuse as children and from controls. These findings are consistent with the experimental rodent findings, and suggest that methylation of receptor sites mediates the association between early care and stress responsiveness. AmygdalaThe amygdala performs a primary role in the formation and storage of memories associated with emotional events. The amygdala undergoes rapid development within the first several years of life and is particularly susceptible to early adversity (e.g., Chareyron et al., 2012). Relative to low-risk children, abused and neglected children show behavioral and emotional difficulties that are consistent with effects on the amygdala, such as internalizing problems, heightened anxiety, and emotional reactivity (Ellis et al., 2004; Kaplow and Widom, 2007; Tottenham et al., 2009; van Ijzendoorn and Juffer, 2006; Zeanah et al., 2009) and deficits in emotional processing (Dalgeish et al., 2001; Pollak et al., 2000; Vorria et al., 2006). Figure 4-2 illustrates structures in the medial temporal lobe critically involved in emotion (amygdala) and learning and memory (hippocampus). Most studies have found no evidence that the structure of the amygdala is affected by abuse or neglect (De Bellis et al., 2001b; Tottenham and Sheridan, 2010; Woon and Hedges, 2008). However, Tottenham and colleagues (2010) and Mehta and colleagues (2009) found that amygdala volume was enlarged among children following institutionalized care, although this finding was not replicated by Sheridan and colleagues (2012) among a similar population. Importantly, both the Mehta et al. and Sheridan et al. studies did find a dramatic reduction in total brain volume, meaning that these children had physically smaller brains. Functional magnetic resonance imaging (fMRI) studies have shown that early adversity leads to a sensitized amygdala. Relative to comparison children, previously institutionalized children showed heightened amygdala activity in response to fearful faces compared with neutral faces (Tottenham et al., 2011). Similarly, Maheu and colleagues (2010) found that children with a history of abuse or neglect showed greater activation of the left amygdala in response to fearful and angry relative to neutral faces. Hippocampus, Learning, and MemoryThe hippocampus (see Figure 4-2) plays an important role in learning and memory (Andersen et al., 2007; Ghetti et al., 2010; Otto and Eichenbaum, 1992) and, like the amygdala, matures rapidly over the first months and years of life (Lavenex et al., 2007). The hippocampus appears to be particularly susceptible to stress early in life (Gould and Tanapat, 1999; Sapolsky et al., 1990) and plays a role in modulating the response of the HPA axis to stressors, as binding of cortisol to hippocampal receptors serves to turn off the HPA axis response (Kim and Yoon, 1998). Damage to the hippocampus due to abuse or neglect can have negative consequences for its roles in regulation of the stress response system and in memory formulation (de Quervain et al., 1998; Sheridan et al., 2012). Most studies have found no evidence of hippocampal volume deficits among abused children compared with healthy, nonabused control children (De Bellis et al., 1999, 2001a, 2002). Among adults, however, decreased hippocampal volume has been linked with the experience of childhood physical and sexual abuse (Andersen and Teicher, 2004; Andersen et al., 2008; Schmahl et al., 2003; Woon and Hedges, 2008). Nonetheless, relatively smaller hippocampal volumes in abused adults may be specific to PTSD rather than abuse itself (Kitayama et al., 2005). Prefrontal Cortex and Executive FunctionsThe prefrontal cortex (see Figure 4-2) is responsible for a variety of higher-order “executive” functions (Miller and Cohen, 2001). The development of the prefrontal cortex is protracted, extending from birth into the third decade of life (Gogtay et al., 2004; Rubia et al., 2006; Sowell et al., 2003). Prefrontal systems are especially sensitive to experiences of early adversity (Hart and Rubia, 2012; McLaughlin et al., 2010). Evidence is mixed with regard to structural changes in the prefrontal cortex following abuse and neglect, with some studies showing smaller volumes of the right orbitofrontal cortex, right ventral-medial prefrontal cortex, and dorsolateral prefrontal cortex (Hanson et al., 2010); some showing decreased grey matter volume in the prefrontal cortex in children with interpersonal trauma and PTSD symptoms (Carrion et al., 2008); some showing the opposite effect (Carrion et al., 2009; Richert et al., 2006); and still others showing no effect after controlling for total brain volume (De Bellis et al., 2002). Despite mixed evidence regarding structural changes in the prefrontal cortex, a number of studies suggest that abuse and neglect are associated with functional changes in the prefrontal cortex and related brain regions. In particular, children with trauma experiences show patterns of neural activation during tasks requiring executive function that are similar to patterns observed in children with attention-deficit hyperactivity disorder (ADHD) (e.g., Carrion et al., 2008). Consistent with these findings among abused and neglected children, previously institutionalized children and adolescents have been found to demonstrate disruptions in the prefrontal network that is associated with inhibitory control. For example, Mueller and colleagues (2010) found that children with a history of neglect or institutional care showed greater activation in several regions of the prefrontal cortex (e.g., left inferior frontal cortex, anterior cingulate cortex) during response inhibition trials of a go/no-go task compared with children without a history of neglect. Similar findings have been reported by McDermott and colleagues (2012) and Loman and colleagues (2009) among currently and previously institutionalized children. Corpus CallosumThe corpus callosum facilitates communication between the two hemispheres of the brain (Giedd et al., 1996a,b; Kitterle, 1995). The white matter fibers composing the corpus callosum are myelinated throughout childhood and adulthood (Giedd et al., 1996a; Teicher et al., 2004), which allows faster, more efficient transmission (Bloom and Hynd, 2005). Myelinated regions such as the corpus callosum are susceptible to the impacts of early exposure to high levels of cortisol, which suppress the glial cell division critical for myelination. Retrospective/cross-sectional studies have found abuse and neglect to be associated with structural changes in the corpus callosum. Teicher and colleagues (2004) compared corpus callosum volume in adults with different abuse and neglect experiences. The total corpus callosum area of the abused children was smaller than that of both healthy control children and children with psychiatric disorders and no abuse or neglect. Other findings suggest that gender may moderate these effects, with the effects being more pronounced among males than females (De Bellis and Keshavan, 2003; De Bellis et al., 1999, 2002; Teicher et al., 1997). Sheridan and colleagues (2012) performed structural MRIs on children enrolled in the Bucharest Early Intervention Project, described previously in this chapter. In a follow-up of 8- to 11-year-olds, Sheridan and colleagues (2012) found smaller total white and gray matter volume and smaller posterior corpus callosum volume among children who had been institutionalized relative to those who had never been institutionalized. By middle childhood, however, there were no significant differences in total white matter volume or posterior corpus callosum volume between the never-institutionalized (community) children and the foster care children. These early differences in corpus callosum may be associated with less efficient cognitive functioning among children who experience early adversity. Influence of Early Profound Neglect on Brain Electrical ActivityThe influence of profound neglect early in life has been examined using electroencephalography (EEG) and event-related potentials (ERPs). ElectroencephalographyEEG measurements of the brain's electrical activity can serve as a coarse metric for brain development. Most work on EEG in the context of neglect has been performed on children with a history of institutional care. The most extensive study of brain electrical activity among children with a history of institutional care was conducted with the children enrolled in the prospective, longitudinal Bucharest Early Intervention Project. At baseline (mean age 20 months), prior to random assignment to continued institutional care or foster care, institutionalized children showed higher levels of theta power (low-frequency brain activity) and lower levels of alpha and beta power (high-frequency activity) compared with children who were not institutionalized (Marshall et al., 2004). The pattern of activity observed in institutionalized children suggests a maturational delay or deficit in cortical development associated with an extreme form of neglect (Marshall et al., 2004). The profiles are similar to patterns found among children with ADHD (Barry et al., 2003; Harmony et al., 1990). At follow-up, as a group, children assigned to foster care did not differ from the care-as-usual group (Marshall et al., 2008). However, the subset of children placed in foster care before 2 years of age showed EEG activity that more closely resembled that of the never-institutionalized group than the care-as-usual group. Overall, then, “institutionalization led to dramatic reductions in brain activity (as reflected in the EEG), whereas placement in foster care before 2 years of age led to a more normal pattern of EEG activity” (Nelson et al., 2011, p. 139). This last finding was replicated when the children were 8 years old (Vanderwert et al., 2010). Specifically, previously institutionalized children placed in foster care before about 2 years of age had patterns of brain activity that resembled those of never-institutionalized children, whereas children placed in foster care after 2 years of age had patterns of brain activity that resembled those of children randomly assigned to institutional care. Event-Related PotentialsERPs measure changes in the brain's electrical activity in response to an internal or external stimulus or event. The components of the ERP (i.e., positive and negative deflections) can be quantified in terms of latency, amplitude, and location/distribution on the scalp. The P300 (i.e., positive deflection occurring approximately 300 ms after a stimulus) is associated with attention to emotionally evocative visual stimuli, such as emotional faces (Eimer and Holmes, 2007; Olofsson et al., 2008). Whereas nonabused children show similar P300 activity across emotional expressions, abused children show larger P300s to angry target faces (Pollak et al., 1997, 2001), a finding consistent with behavioral evidence of enhanced attention to angry faces among abused children.
COGNITIVE, PSYCHOSOCIAL, AND BEHAVIORAL OUTCOMESCognitive DevelopmentThere is a long history of research exploring the effects of child abuse and neglect on cognitive development. Studies have examined executive functioning and attention, as well as academic achievement. Executive Functioning and AttentionAs discussed earlier, some studies have found that child abuse and neglect have effects on the prefrontal cortex, a brain structure centrally involved in executive functioning. Executive functioning refers to higher-order cognitive processes that aid in the monitoring and control of emotions and behavior (Lewis-Morrarty et al., 2012). Included among executive functions are “holding information in working memory, inhibiting impulses, planning, sustaining attention amid distraction, and flexibly shifting attention to achieve goals” (Lewis-Morrarty et al., 2012, p. 2). Executive functioning abilities develop rapidly between the ages of 3 and 6 years, but continue to develop through at least the second decade of life. Children who experience abuse and neglect appear to be especially at risk for deficits in executive functioning, which have implications for behavioral regulation. Extreme neglect, as seen in institutional care, has been related to executive functioning in a number of studies conducted by the Bucharest Early Intervention Project team (McDermott et al., 2012). For example, McDermott and colleagues (2012) found that children who were randomly assigned to foster care showed better performance on an executive functioning task (i.e., a go/no-go task requiring inhibitory control) than children who were randomly assigned to treatment as usual. The assessments of executive functioning were conducted when children were 8 years old. Similar findings among comparably aged internationally adopted children (with histories of institutionalization) have been reported (e.g., Loman et al., 2013). These findings suggest that extreme forms of neglect may interfere with the development of executive functioning. Problems in regulating attention represent one of the most striking deficits seen among children who have experienced severe early deprivation in institutional settings (Gunnar et al., 2007; Kreppner et al., 2001). Gunnar and colleagues (2007) found that problems with inattention or overactivity were more pronounced among children who had experienced early institutional care than among those who had been adopted internationally without early institutional care. Kreppner and colleagues (2007) found that many children who had been adopted following institutional care showed problems with inattention or overactivity, but that such problems were usually seen in combination with reactive attachment disorder, quasi-autistic behaviors, or severe cognitive impairment. Using NSCAW data, Heneghan and colleagues (2013) examined mental health problems in teens older than age 12 who were the subject of a child welfare agency investigation. They found that 18.6 percent of abused and neglected teens scored positively for ADHD, compared with 5 percent of children and 2.5 percent of adults in the general U.S. population (APA, 2013c). Likewise, Briscoe-Smith and Hinshaw (2006) studied a sample of 228 girls with and without ADHD and with and without a history of abuse and neglect, finding that the girls with ADHD had a statistically significant heightened risk of having a documented history of abuse or neglect, as indicated by substantiated child protective services, parental, or school report. Some studies have found preliminary differences in the characteristics of ADHD displayed by children with and without a history of abuse or neglect (Webb, 2013). For example, Becker-Blease and Freyd (2008) studied a small community sample of 8- to 11-year-old children in which ADHD and abuse history were assessed by parent report. They found that children with a history of abuse displayed more severe impulsivity and inattention than nonabused children with ADHD, but the groups did not differ on measures of hyperactivity (Becker-Blease and Freyd, 2008). A number of studies have found evidence that children who experience abuse and neglect show deficits in executive functioning and attention (Arseneault et al., 2011; De Bellis et al., 2009; Fisher et al., 2011; Lewis et al., 2007; Spann et al., 2012). Pears and colleagues (2008) found that abuse and neglect were associated with generally lower cognitive functioning among preschoolers. Lewis and colleagues (2007) found that 4-year-old children who had experienced abuse or neglect and were in foster care showed poorer inhibitory control on a Stroop-like task relative to comparison children, despite similar levels of performance on a control task. Spann and colleagues (2012) found that physical abuse and neglect were associated with diminished cognitive flexibility on the Wisconsin Card Sorting Task among adolescents. Academic AchievementAbuse and neglect increase children's risk for experiencing academic problems. Several studies suggest that abuse versus neglect matters, with neglect being especially predictive of academic underachievement (Briere et al., 1996; Jonson-Reid et al., 2004; Nikulina et al., 2011). Other studies failed to find differences between abuse and neglect, with both predicting achievement problems (e.g., Barnett et al., 1996; Crozier and Barth, 2005; Eckenrode et al., 1993; Jaffee and Gallop, 2007; Kurtz et al., 1993; Leiter and Johnsen, 1997). On balance, the evidence suggests that both abuse and neglect are predictive of academic problems. Perez and Widom (1994) found that child abuse and neglect had a significant impact on reading ability, IQ scores, and academic achievement. For example, 42 percent of abused and neglected children completed high school, compared with two-thirds of the matched comparison group without histories of abuse and neglect. The average IQ score for the abused and neglected children was about one standard deviation below the average for the control group; this association was significant after controlling for age, race, gender, and social class (Perez and Widom, 1994). Using NSCAW data, Jaffee and Maikovich-Fong (2011) found that chronically abused or neglected children had lower IQ scores than situationally abused or neglected children. The effect of chronic abuse or neglect on IQ scores remained significant after controlling for the effects of caregiver educational level on IQ. Leiter and Johnsen (1997) found that effects of abuse and neglect on school performance were cumulative, with more episodes of abuse and neglect being associated with poorer outcomes. Abuse and neglect predicted entry into special education after controlling for early medical conditions (Jonson-Reid et al., 2004). Jonson-Reid and colleagues (2004) found that 24 percent of the abused and neglected children entered special education, compared with 14 percent of those with no record of abuse or neglect. Further, every additional report of abuse or neglect before the age of 8 led to an increase of 7 percent in entry into special education. Thompson and colleagues (2012) found that expectations of future academic success were adversely affected by previous experiences of abuse and neglect, with these expectations having powerful self-fulfilling possibilities (Ross and Hill, 2002). Psychosocial and Behavioral OutcomesGiven that child abuse and neglect are social experiences that undermine the ability to trust in caregivers, either because caregivers are frightening (as in cases of abuse) or because they fail to protect or provide care (as in cases of neglect), it makes sense that children who experience abuse and neglect are at risk for interpersonal problems. At the most proximal level, problems are seen in children's ability to form trusting attachments to their parents. But not surprisingly, the effects also are seen in such areas as children's processing of emotion (e.g., overly vigilant of angry faces), their attributions of others' intent (e.g., assuming that intentions are malevolent when they are ambiguous), and difficulties with peers (e.g., being the victim or perpetrator of bullying or violence). Problems also are seen in internalizing symptoms, such as anxiety and depression, and externalizing symptoms, such as conduct disorder and substance use. AttachmentChildren develop secure attachments to parents who are responsive to them when they are distressed (Ainsworth, 1978). Children typically develop insecure (avoidant or resistant) attachments when parents are unresponsive or inconsistent in responsiveness, but not frightening or bizarre (e.g., Lyons-Ruth et al., 1993; Schuengel et al., 1998). Secure, avoidant, and resistant attachments are referred to as organized attachment strategies because they are organized around the caregiver's availability and provide a child a template for dealing with distress. On the other hand, disorganized attachment represents a breakdown in or a lack of strategy for dealing with distress when in the parent's presence (Main and Solomon, 1990). Disorganized attachments are the most problematic in terms of outcomes for children. Relative to organized attachment, disorganized attachment is most predictive of long-term problems, especially externalizing symptoms (Fearon et al., 2010). Fearon and colleagues (2010) found strong evidence for a link between disorganized attachment and later externalizing symptoms through a meta-analysis of 34 studies involving 3,778 participants. Child abuse and neglect are predictive of disorganized attachment, as well as insecure attachment more generally. A meta-analysis conducted by Cyr and colleagues (2010) included the 10 studies that have examined attachment quality with samples of children who have experienced abuse and neglect. The effect size was large for both disorganized and insecure attachment. Although abuse was more strongly related to disorganized attachment and neglect to insecure attachment, both abuse and neglect were associated with both types of attachment. These results are consistent with theory and with other empirical findings suggesting that when parents are either frightening or unavailable, children fail to develop a secure attachment to them. Nonetheless, the effects of having more than five socioeconomic risk factors were comparable to those of child abuse and neglect, indicating that multiple challenges to parental functioning had significant effects on attachment regardless of whether these effects were seen in child abuse and neglect. In early childhood, abused or neglected children may develop attachment disorders resulting from and following pathogenic care that inhibits a young child's ability to form selective attachments (Hornor, 2008). Childhood attachment disorders are phenomena distinct from insecure, disorganized, or nonexistent attachment types; they have been redefined in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-V) to include two distinct disorders: reactive attachment disorder and disinhibited social engagement disorder (APA, 2013a,b). Reactive attachment disorder involves inhibited or emotionally withdrawn behavior, including rarely seeking and responding to comforting; it results from a lack of or incompletely formed selective attachments to adult caregivers (APA, 2013a). Disinhibited social engagement disorder is marked by a pattern of overly familiar behavior with strangers; it may occur even in children with established or secure attachments. Previously, each attachment disorder was considered the inhibited or disinhibited type of reactive attachment disorder, respectively. Zeanah and colleagues (2004) studied the prevalence of attachment disorders among 94 toddlers in foster care whose abuse or neglect cases had been substantiated and who were enrolled in an intervention program; they found that the prevalence of attachment disorders reached 38-40 percent. Lyons-Ruth and colleagues (2009) examined socially indiscriminate attachment behavior in a sample of mother-child dyads that included pairs referred to a clinical service because of problematic caregiving and comparison pairs matched on socioeconomic status. They found that 18-month-olds displayed socially indiscriminate attachment behavior only if they had a history of abuse or neglect, or their mother had a history of psychiatric hospitalizations. Both disorders also have been identified in children exposed to neglectful institutional care in Romania who were later adopted into middle-class families in the United Kingdom (Smyke et al., 2002; Zeanah et al., 2002), although the disinhibited type of reactive attachment disorder (as defined in DSM-IV) has been found to be much more prevalent than the inhibited type (O'Connor et al., 2003). Furthermore, findings from the Bucharest Early Intervention Project study indicate that the inhibited type of reactive attachment disorder declined significantly once institutionalized children were placed in foster care, but the disinhibited type proved more persistent (Smyke et al., 2002; Zeanah and Gleason, 2010). Emotion RegulationInfants have limited capacities to regulate their own emotions and are dependent on caregivers to help them deal effectively with distress (Tronick, 1989). Indeed, infants and young children are highly attuned and responsive to their parents' emotions and use parental emotional signals to guide their behavior (Klinnert et al., 1983; Malatesta and Izard, 1984). The scaffolding important for the development of emotion regulation is challenged in abusing or neglecting families. When children feel upset or distressed, parents' availability and soothing presence can help them feel that they can cope with the strong negative affect, such that they are able to develop autonomous and effective means of regulating emotions over time. When children regulate their emotions well, they react to challenge with flexible and socially acceptable responses (Cole et al., 1994; Kim and Cicchetti, 2010). Abused and neglected children, however, may not have such scaffolding experiences. It is likely that abused and neglected children experience not only a lack of modeling and support and an absence of positive affect but also harsh, inconsistent, and insensitive parenting (Shipman and Zeman, 2001). In the case of abuse, parents often respond in threatening or unpredictable ways to children's distress (Milner, 2000). In the case of neglect, parents may be unresponsive or nonempathic. As a result of either response, children are at risk of failing to develop effective strategies for regulating emotions (Cicchetti et al., 1995; Kim and Cicchetti, 2010; Rogosch et al., 1995). An initial, key task in regulating emotions is processing of cues. Studies have examined differences among children who have experienced abuse and neglect in how readily they identify angry, sad, and happy faces (Pollak and Sinha, 2002; Pollak and Tolley-Schell, 2003; Pollak et al., 2000; Shackman et al., 2007). Pollak and Sinha (2002) found that the threshold for detecting anger in the face was lower among abused than nonabused children; there were no differences in processing happy faces. Thus, these children appear to have a bias toward angry faces rather than a general deficit in processing faces. Pollak and Sinha (2002) point out that it is useful to identify emotions in others based on less than full information. Abused children's bias toward attributing angry or sad affect may be adaptive when living with parents whose anger may be an important threat cue (Belsky et al., 2012); nonetheless, it comes at the cost of assuming hostile intent too readily under benign conditions, leading to aggressive responses that would not have been evoked had attributions been different (Dodge et al., 1995). Neglected children, on the other hand, generally are not as good as nonneglected children at identifying facial expressions, showing a general deficit (Pollak et al., 2000). Emotion regulation can be seen as key to a number of the constructs considered in this chapter. Problems in regulating emotion are associated with externalizing behaviors, such as aggression and behavior problems (Eisenberg et al., 2001; Kim and Cicchetti, 2010); internalizing behaviors, such as depression (Cole et al., 2008; Maughan and Cicchetti, 2002); and challenges in peer relations (Kim and Cicchetti, 2010; Rogosch et al., 1995). Emotion regulation can be seen, then, to have effects both on children's own affect and on their behavioral reactions, which then have implications for their relationships with others. Peer RelationsChildren's relationships with their peers are critical to their sense of well-being. Abused and neglected children have problematic peer relations at disproportionately high rates (Kim and Cicchetti, 2010), as do children with a history of institutional care (Almas et al., 2012). Chronicity of child abuse and neglect predict peer relations, as reported by teachers, at age 8 (Graham et al., 2010). Problematic emotion regulation (Shields and Cicchetti, 2001) and higher levels of aggression and withdrawal (Rogosch et al., 1995) found in abused and neglected children can become apparent to peers when frustrations and challenges arise in school and playground environments. Externalizing ProblemsExternalizing behavior refers to problem behaviors that are manifested externally (rather than internally, as in the case of depression and anxiety). Findings from several studies indicate that children who have experienced abuse and neglect are at greater risk for a number of externalizing behaviors, including conduct disorders, aggression, and delinquency (Lansford et al., 2002, 2009; Lynch and Cicchetti, 1998; Stouthamer-Loeber et al., 2001; Thornberry et al., 2010). Oppositional defiant disorder and conduct disorder Studies have reported significant associations between a history of childhood abuse or neglect and various conduct problems, including those classified as oppositional defiant disorder or conduct disorder. Oppositional defiant disorder is indicated by a frequent or persistent pattern of angry or irritable mood, argumentative or defiant behavior, and vindictiveness (APA, 2013a). Its symptoms usually first appear during early childhood, and it often precedes conduct disorder, anxiety disorders, or major depressive disorder. Conduct disorder is indicated by a repetitive or persistent pattern of behavior that violates the basic rights of others or major societal norms or rules, including aggression toward people or animals, destruction of property, deceitfulness or theft, and serious violations of rules (APA, 2013a). Conduct disorder can begin in childhood or adolescence; however, childhood-onset conduct disorder is more often preceded by oppositional defiant disorder, more persistent into adulthood, and more likely to include aggressive behavior than adolescence-onset conduct disorder. Both disorders also frequently co-occur with ADHD. In a study using a community sample, Dodge and colleagues (1995) found that children who were physically abused before age 5 were 4 times more likely than nonabused children to display externalizing conduct problems in grade 3 and 4. Likewise, Kaplan and colleagues (1998) found that adolescents (aged 12-18) with substantiated cases of physical abuse were more likely to display conduct disorder or oppositional defiant disorder at the time of the study (odds ratio = 5.98) than the matched nonabused comparison group. Fergusson and colleagues (2008) found that childhood sexual abuse was associated with higher rates of conduct disorder in young adulthood. Furthermore, they found that childhood physical abuse was not associated with conduct disorder when sexual abuse was included in the model. Additional environmental and individual factors that interact with abuse or neglect to increase the likelihood of conduct disorder or oppositional defiant disorder include exposure to parental divorce (Afifi et al., 2009), interparental violence (Boden et al., 2010), and community violence (McCabe et al., 2005), as well as gender, with males more likely to display conduct disorder (Boden et al., 2010). Aggression Manly and colleagues (2001) found that children who had experienced severe emotional abuse only as infants or severe physical abuse only as toddlers were more aggressive and showed more externalizing symptoms as school-aged children than children without a history of abuse or neglect. The severity of abuse experienced predicted aggressiveness and externalizing symptoms in middle childhood. Although abuse experienced only in early childhood had lasting effects, abuse experienced beyond early childhood also had effects on aggression and externalizing symptoms, and the most problematic effects were seen for children subjected to chronic, severe abuse (Manly et al., 2001). Rogosch and colleagues (1995) found that physically abused children showed both aggressive behaviors and social withdrawal during peer interactions. Along these lines, abused and neglected children were disproportionately likely to be both bullies and victims of aggression, effects that were mediated by emotion dysregulation (Shields and Cicchetti, 2001). At odds with these findings, Kotch and colleagues (2008) found that children who experienced neglect in their first 2 years of life showed more aggression toward peers at ages 4, 6, and 8 relative to children without a history of abuse or neglect. Indeed, in that study, other subgroups (children who were abused or who were neglected at older ages) did not show an increased likelihood of aggression. Hostile attributional bias refers to the tendency to assume that someone intended harm when circumstances were ambiguous but a negative outcome was experienced. For example, if a peer spilled milk on a child, the child could assume that the action was benign (unintentional) or intentional, with the latter representing a hostile attributional bias. When children assume that such an action was intentional, they are likely to act aggressively in response (Dodge et al., 1995). Physically abused children are more likely than other children to show such attributional biases (Dodge et al., 1995). Price and Glad (2003) found that these effects were seen in boys only and were associated with frequency of abuse. Such biases can lead to a self-fulfilling prophecy whereby children anticipate that someone intends them harm and react in a hostile way, which then elicits a hostile response (Dodge et al., 1995). Internalizing ProblemsInternalizing problems—problems that are manifested internally—include symptoms of depression and anxiety. Child abuse and neglect have been found to put children at increased risk of internalizing symptoms from early childhood through adolescence and adulthood (Dubowitz et al., 2002; Thornberry et al., 2001; Widom et al., 2007a). Dubowitz and colleagues (2002) found that neglect was associated with internalizing problems for 3- and 5-year-old children. Swanston and colleagues (1997) found that sexually abused children had a significantly higher average score on depression measures than a control group just 5 years after the abuse occurred, after adjusting for individual differences in age and sex, as well as contextual factors such as socioeconomic status, family functioning, mother's mental health, and number of negative life events. Trickett and colleagues (2001) found that a sample of sexually abused girls had significantly higher rates of self-reported depression than a comparison group of nonabused females. At follow-up, approximately 7 years later, rates of depression were found to be significantly higher among the sexually abused group, excluding a subset whose experience of abuse was characterized chiefly by multiple perpetrators and a relatively short duration. The heightened risk of depression extends beyond childhood to adolescence and adulthood. Multiple studies have found clear links between child abuse and neglect and depression in adolescence (e.g., Fergusson et al., 2008; Heneghan et al., 2013; Lansford et al., 2002). Brown and colleagues (1999) found that child abuse and neglect were associated with a nearly threefold increase in the rate of depression in adolescence, although this risk was diminished after controlling for other adverse conditions. Gilbert and colleagues (2009b) cite a body of studies reporting adjusted odds ratios ranging from 1.3 to 2.4 for depression after childhood among those subjected to abuse and neglect as children. Among adults, Brown and colleagues (1999) found that the increased risk of depression associated with child abuse and neglect remained when other factors were covaried, consistent with findings that more than one-third of abused or neglected children show symptoms of major depressive disorder by their late 20s (Gilbert et al., 2009b). Likewise, Widom and colleagues (2007a) followed a group of individuals who had experienced abuse and/or neglect in childhood and a matched comparison group into young adulthood and found that experiencing childhood physical abuse and multiple types of abuse increased the lifetime risk for a diagnosis of major depressive disorder. A growing body of research examines whether different types and combinations of abuse or neglect in childhood result in different levels of risk for the development of depressive symptoms. The results in this domain are mixed, with strong evidence that sexual and physical abuse in childhood are associated with depression later in life (e.g., Heneghan et al., 2013), but mixed evidence that neglect increases risk for depression independent of contextual factors. Many studies have found child sexual abuse to have large and independent effects on risk for depression later in life. For example, Fergusson and colleagues (2008) found that young adults who reported a history of childhood sexual abuse had mental health disorders, including depression, at a rate 2.4 times higher than that among those not exposed to such abuse. By contrast, Widom and colleagues (2007a) found that child sexual abuse was not associated with an elevated risk of major depressive disorder relative to matched controls, although physical abuse or multiple kinds of abuse did increase the risk for lifetime major depressive disorder. Additional studies have found that physical abuse increased the risk for adult depression (e.g., Brown et al., 1999). Some studies have found that neglect did not increase the risk for depression when statistical models included contextual factors (Nikulina et al., 2011), although Widom and colleagues (2007a) found that neglect increased risk for current major depressive disorder relative to matched controls in adulthood. As discussed in the section on individual differences later in this chapter, researchers also have examined how the timing (Dunn et al., 2013; Thornberry et al., 2001) and severity (Fergusson et al., 2008) of abuse and neglect affect the risk of developing depression. Other factors throughout the life course, such as the presence or absence of social support (Sperry and Widom, 2013) and exposure to multiple traumas (Banyard et al., 2001) or stressful life events in adulthood (Power et al., 2013), have been found to interact with childhood experiences of abuse and neglect to influence the risk of developing depression later in life. DissociationDissociation is defined as a “disruption of and/or discontinuity in the normal, subjective integration of one or more aspects of psychological functioning, including—but not limited to—memory, identity, consciousness, perception, and motor control” (Spiegel et al., 2011, p. 19). Dissociation can be measured reliably and validly in children, adolescents, and adults (Briere et al., 2001; Keck Seeley et al., 2004; Lanktree et al., 2008; van Ijzendoorn and Schuengel, 1996; Wherry et al., 2009). Child abuse and neglect have been associated with dissociation among both preschool-aged and elementary-aged children (Hulette et al., 2008, 2011; Macfie et al., 2001), as well as among adults (van Ikzendoorn and Schuengel, 1996). The existence of a subgroup of PTSD patients with high levels of dissociation has been demonstrated in clinical (Lanius et al., 2013; Putnam, 1997), psychophysiological (Griffin et al., 1997), neuroimaging (Lanius et al., 2013), and epidemiological (Stein et al., 2013) research. As a result, DSM-V is adding a dissociative subtype to the PTSD diagnosis (Spiegel et al., 2011a) (see the discussion of PTSD on p. 139). High scores on dissociation measures have proven to be a predictor of externalizing behavior in children (Kisiel and Lyons, 2001; Shapiro et al., 2012; Yates et al., 2008). In adults, high levels of dissociation are associated with refractoriness to standard treatments for a number of psychiatric conditions, as well as increased comorbidity (Jans et al., 2008; Kleindienst et al., 2011; Wolf et al., 2012; Zanarini et al., 2011). A meta-analysis of 55 studies (Cyr et al., 2010) links abuse with disorganized attachment. Grienenberger and colleagues (2005) found that mothers who engaged in disrupted affective communication with their infants at 4 months (as measured using the AMBIANCE scale) were more likely to have toddlers who were classified as disorganized at 14 months. In turn, disorganized attachment at 14 months predicted high dissociation scores at age 20 years (Lyons-Ruth, 2008). Disorganized attachment assessed during the child's second year predicted elevated levels of self-reported dissociation in mid-adolescence (age 16 years) (Carlson, 1998) and early adulthood (age 19) (Ogawa et al., 1997). Based on findings from the Minnesota Mother-Child Project, Egeland and Susman-Stillman (1996) propose that dissociation may act as a mediator of child abuse across generations. In a longitudinal study of sexually abused girls followed into parenthood, Kim and colleagues (2010) found that increased dissociation, together with a history of self-reported punitive parenting as a child, predicted whether a mother would parent her own children in a harsh and punitive manner. Thus, a tentative generational loop can be hypothesized in which harsh and abusive parenting increases the risk for higher levels of dissociation in childhood and adolescence, which in turn increases the risk for impulsive behavior and harsh parenting of offspring. Further research, especially with a longitudinal design, is warranted to determine whether this hypothesized generational pattern of transmission represents an early opportunity for prevention of abuse in the next generation. Posttraumatic Stress DisorderIn DSM-V, PTSD is classified as a trauma- and stressor-related disorder, a change from its previous classification as an anxiety disorder. PTSD develops following “exposure to actual or threatened death, serious injury, or sexual violation,” including directly experiencing the traumatic event, witnessing the event firsthand, learning that an actual or threatened violent or accidental death occurred to a family member or close friend, and experiencing repeated or extreme firsthand exposure to the details of the traumatic event (APA, 2013c). Behavioral symptoms of PTSD are divided into four categories: intrusion or reexperiencing, avoidance, negative alterations in cognition and mood, and alterations in arousal and reactivity (National Center for PTSD, 2013). Experiences of child abuse and neglect involve traumatic events that are often violent, invasive, and coercive (Kearney et al., 2010). Furthermore, secondary trauma may result from experiences of child abuse and neglect, including separation from family or homelessness, which may also trigger a PTSD response (Wechsler-Zimring et al., 2012). A number of prospective and retrospective studies have found elevated rates of PTSD among individuals with a history of abuse and neglect (Chen et al., 2010; Kearney et al., 2010; Tolin and Foa, 2006; Weich et al., 2009; Widom, 1999). Numerous studies have found that PTSD was preceded by abuse and neglect; links with sexual abuse were especially strong (Chen et al., 2010; Gregg and Parks, 1995; Kendall-Tackett et al., 1993; Tolin and Foa, 2006; Weich et al., 2009; Widom, 1999). Kearney and colleagues (2010) report PTSD rates of 20-50 percent among youth who had been sexually abused, 50 percent among youth who had been physically abused, and 33-50 percent among youth who had experienced neglect combined with exposure to domestic violence. Kolko (2010) found that nearly 20 percent of youth in out-of-home care showed posttraumatic symptoms. Widom (1999) found increased risk for PTSD among adults who had experienced abuse and neglect as children, with 23 percent of those who had been sexually abused, 19 percent of those who had been physically abused, and 17 percent of those who had been neglected meeting criteria for PTSD at age 29, compared with 10 percent of the comparison group. Some evidence indicates that PTSD may mediate the association between childhood abuse and neglect and later adverse outcomes. Wolfe and colleagues (2004) found that boys who had been abused or neglected in childhood and displayed a greater number of PTSD symptoms were at higher risk of perpetrating emotional abuse in a dating relationship compared with abused or neglected boys who displayed fewer trauma symptoms. Weierich and Nock (2008) found that the specific PTSD symptoms of reexperiencing, avoidance, and numbing mediated the relationship between childhood experiences of abuse and neglect and nonsuicidal self-injury. In a study of adult women survivors of childhood sexual abuse, Ginzburg and colleagues (2006) found that severe childhood maltreatment, including sexual abuse as well as other types of abuse or neglect, was significantly associated with experiencing high levels of dissociation in conjunction with PTSD, while less severe childhood maltreatment was not significantly associated with the dissociative subtype. Avery and colleagues (2000) examined PTSD and key areas of functioning based on interviews with sexually abused children and their nonoffending parents. Compared with sexually abused girls with low scores on the Child Posttraumatic Stress Reaction Index, sexually abused girls with higher scores expressed more worries; reported increased problems with sleep, appetite, headaches, and stomachaches; reported increased depression and suicidal ideation; displayed more problems in school functioning; and had higher levels of family disruption. Personality DisordersEvidence links child abuse and neglect with personality disorders. Johnson and colleagues (1999) found that adults with a history of abuse and neglect (as indicated by records and/or self-report) had a fourfold increase in personality disorders relative to those without a history of abuse or neglect. Physical abuse was associated with elevated antisocial and depressive personality disorder symptoms; sexual abuse was associated with elevated borderline personality disorder symptoms; and neglect was associated with elevated symptoms of antisocial, avoidant, borderline, narcissistic, and passive-aggressive personality disorders, as well as with attachment difficulties and other interpersonal and psychological problems. Widom (1998) reports an increase in risk for antisocial personality disorder for both males and females with a history of abuse and neglect. In a subsequent study, Widom and colleagues (2009) report an increase in risk for borderline personality disorder in males only, suggesting that there may be sex differences in the consequences of abuse and neglect. Natsuaki and colleagues (2009) found that personality problems, although not diagnosed personality disorders, worsened as adolescence progressed.
HEALTH OUTCOMESChild abuse and neglect have effects on a number of health outcomes, from growth to illness to obesity. Connections have been found between problematic neurobiological outcomes of child abuse and neglect and health. One plausible mechanism for these effects relates to the purported frequent or chronic activation of the HPA axis. As discussed previously, the HPA axis is designed for responding in crises. Growth and Motor DevelopmentIn their most extreme forms, abuse and neglect are associated with stunted growth. Children living in institutional environments (Johnson et al., 2010) or adopted from highly neglecting institutional environments (Johnson and Gunnar, 2011) sometimes show very delayed growth in height and head circumference. Olivan (2003) found that children placed in foster care between ages 24 and 48 months were significantly below normal for height, weight, and head circumference. Similarly, Chernoff and colleagues (1994) found that most children entering foster care had an abnormal physical screen involving at least one body system, and on average weighed less and were shorter than comparison children. Gross motor development often is delayed among children with a history of institutional care who have then been adopted internationally (Dobrova-Krol et al., 2008; Roeber et al., 2012). Roeber and colleagues (2012) found that children adopted from institutional settings showed motor system delays, with greater balance delays being predicted by length of time institutionalized and bilateral coordination delays being predicted by severity of deprivation. Rapid gains are seen after placement in adoptive homes, however (Pomerleau et al., 2005). Although somewhat canalized (less responsive to genetic or environmental variations), the development of these gross motor abilities is dependent upon opportunities to engage in motor activities. Note that these findings regarding motor delays may be limited in their application to extreme cases of neglect in which young children are left alone in their cribs or otherwise neglected for extended periods of time. IllnessChild abuse and neglect have been linked to various forms of physical illness as well as various indicators of physical health problems. Adolescents with a history of childhood abuse or neglect report a lower rating of their own health compared with low-risk peers (Bonomi et al., 2008; Hussey et al., 2006). Likewise, more gastrointestinal symptoms were reported by adults who reported having been abused or neglected as children (Walker et al., 1999). To examine whether this association resulted from shared method variance, van Tilburg and colleagues (2010) used data collected from multiple informants among a sample of 845 children enrolled in the longitudinal, prospective Longitudinal Studies of Child Abuse and Neglect. Across informants, youth who had experienced abuse or neglect had an increased likelihood of gastrointestinal symptoms, which often followed or coincided with sexual abuse. In a longitudinal prospective study, childhood abuse and neglect predicted health indices among middle-aged adults (Widom et al., 2012). Both physical abuse and neglect predicted hemoglobin A1C (a biomarker for diabetes) and albumin (a biomarker for liver and kidney function); physical abuse uniquely predicted malnutrition and blood urea nitrogen (a marker for kidney function); neglect uniquely predicted poor peak airflow; and sexual abuse uniquely predicted hepatitis C (Widom et al., 2012). Findings from the Adverse Childhood Experiences study indicate a heightened risk for liver disease, lung cancer, and ischemic heart disease among adults who report multiple adverse experiences in childhood (Brown et al., 2010; Dong et al., 2003, 2004). The adverse experiences measured in the study include emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect, as well as indicators of household dysfunction, such as domestic violence, parental divorce or separation, household member mental illness, household member substance abuse, and household member incarceration. Dong and colleagues (2003) found that the adjusted odds ratio for ever having liver disease ranged from 1.4 to 1.6 for different types of abuse and neglect; among individuals with more than 6 adverse childhood experiences, the adjusted odds ratio was 2.6. Notably, the risk of liver disease was substantially mediated by risk behaviors for liver disease, such as alcohol and drug use and various sexual behaviors. Brown and colleagues (2010) found an association between adverse childhood experiences and an increased risk of lung cancer, which was partially mediated by smoking behavior. In particular, exposure to a large number of adverse childhood experiences was strongly associated with premature death from lung cancer; among individuals who died from lung cancer, those with 6 or more adverse childhood experiences died an average of 13 years earlier than those with no adverse childhood experiences. Likewise, Dong and colleagues (2004) found that adverse childhood experiences increased the likelihood of ischemic heart disease. The association was substantially mediated by both traditional (diabetes, hypertension, physical inactivity, smoking, and obesity) and psychological (anger and depressed affect) risk factors, but the psychological risk factors of anger (adjusted odds ratio of 2.1) and depression (adjusted odds ratio of 2.5) had stronger associations with heart disease than the traditional risk factors. ObesityIn various studies, different forms of child abuse and neglect have been linked with increased body mass index and higher rates of obesity in childhood, adolescence, and adulthood. Some studies link neglect but not abuse to obesity (e.g., Johnson et al., 2002; Lissau and Sorensen, 1994), and some link physical abuse but not neglect (Bentley and Widom, 2009). These differences may be the result of differences in the time points at which obesity is assessed, in sample characteristics, or in the adequacy of controls, or other factors. Knutson and colleagues (2010) found that specific types of neglect (supervisory versus care) predicted obesity at different ages. Care neglect, defined as inattention to such things as provision of adequate food and clothing, predicted body mass index at younger ages, whereas supervisory neglect, defined as parental lack of availability, predicted body mass index at older ages.
ADOLESCENT AND ADULT OUTCOMESWhile a number of the consequences of child abuse and neglect discussed previously in this chapter can be present across childhood, adolescence, and adulthood, this section focuses on behavioral outcomes that manifest specifically in either adolescence or adulthood. Delinquency and ViolenceMaxfield and Widom (1996) found that abuse and neglect experienced in childhood predicted violence and arrests in early adulthood. Adults with a history of abuse and neglect were more likely than adults without such a history to have committed nontraffic offenses (49 percent versus 38 percent) and violent crimes (18 percent versus 14 percent). Victims of childhood physical abuse and neglect were more likely to be arrested for violence (odds ratios 1.9 and 1.6, respectively) after controlling for age, race, and sex. These authors also found that abused and neglected girls were at increased risk for being arrested for violence relative to girls who had not been abused and neglected, with an odds ratio of 1.9. Smith and colleagues (2005) also found that abuse and neglect increase the risk of violent offending in late adolescence and early adulthood. Jonson-Reid and colleagues (2012) found a powerful effect for the number of child abuse reports predicting violent delinquency, with the association being linear for up to three reports. Two of these prospective longitudinal studies also found that sexual abuse increased the risk for general offending, but not violent offending (Smith et al., 2005). Physical abuse appears to be strongly related to violence in girls, as demonstrated in a meta-analysis (Hubbard and Pratt, 2002). There is evidence that childhood abuse increases the risk for crime and delinquency. A number of large prospective investigations in different parts of the United States have documented a relationship between childhood abuse and neglect and juvenile and/or young adult crime (English et al., 2002; Lansford et al., 2007; Maxfield and Widom, 1996; Smith and Thornberry, 1995; Stouthamer-Loeber et al., 2001; Widom, 1989; Widom and Maxfield, 2001; Zingraff et al., 1993). Despite differences in geographic region, time period, youths' age and sex, definition of child maltreatment, and assessment technique, these prospective investigations provide evidence that childhood maltreatment increases later risk for delinquency and violence. Replication of this relationship across a number of well-designed studies supports the generalizability of and increases confidence in the results. Alcohol and Substance UseAs adolescents and adults, those with a history of abuse and neglect have higher rates of alcohol abuse and alcoholism than those without a history of abuse and neglect (Gilbert et al., 2009b; Jonson-Reid et al., 2012). The effects tend to be stronger for women, being seen even when other factors are covaried (Simpson and Miller, 2002; Widom et al., 1995). For example, Widom and colleagues (1995) found no association between a history of abuse and neglect and alcohol use by young men, but found an association for women even after controlling for parental substance use and other correlated variables. A similar pattern of results emerged in a follow-up with these participants about 10 years later, when they were approximately 40 years old. Women with a documented history of child abuse and/or neglect were more likely to drink excessively in middle adulthood than those without such a history (Widom et al., 2007b); again, this difference was not seen in men. Girls with a history of physical abuse tend to start using substances (including alcohol, marijuana, tobacco, etc.) at younger ages than youth without such a history (Lansford et al., 2010). Work by Lansford and colleagues (2010) suggests that this early initiation serves as the mechanism for later substance use in adulthood. Evidence linking abuse and neglect to substance abuse in adulthood is mixed (Gilbert et al., 2009b; Widom et al., 1999), with retrospective and prospective findings differing. For example, Widom and colleagues (1999) describe findings based on defining child abuse and neglect prospectively and retrospectively using self-reports (i.e., following their sample forward and asking adults whether they had been abused or neglected as children). The findings based on these two types of data differed dramatically. The prospective data showed no increase in risk of substance abuse at age 29, whereas the retrospective data showed significant differences. Interestingly, a later follow-up with this sample (Widom et al., 2006) found that in middle adulthood, abused and neglected individuals compared with controls were about 1.5 times more likely to report using any illicit drug (in particular, marijuana) during the past year, and reported use of a greater number of illicit drugs and more substance use–related problems. Findings such as these provide support for the importance of longitudinal studies because without the subsequent follow-up, there would have appeared to be no increase in risk for adults who had experienced childhood abuse or neglect; these findings also illustrate the importance of contextual factors in understanding consequences. Suicide AttemptsExperiences of abuse and neglect in childhood have a large effect on suicide attempts in adolescence and adulthood (Brown et al., 1999; Fergusson et al., 2008; Gilbert et al., 2009b; Widom, 1998). Among adults in their late 20s, Widom (1998) found that 19 percent of those with a history of abuse or neglect had made at least one suicide attempt, as compared with 8 percent of a matched community sample. Fergusson and colleagues (2008) found high rates of suicide among a New Zealand sample as well. These effects are seen for physical and sexual abuse even after accounting for other associated risk factors (Fergusson et al., 2008). Trickett and colleagues (2011) found, through a prospective design, more incidents of self-harm and suicidal behaviors among women who had been sexually abused than among a control group of women who had not been sexually abused. Sexual BehaviorStudies have investigated the association between child abuse and neglect and several aspects of sexual behavior, including early sexual initiation and sexual risk behavior, teen pregnancy, and prostitution and the risk for commercial sexual exploitation of children and adults. Early Sexual Initiation and Sexual Risk BehaviorChildren who experience abuse and neglect may initiate sexual activity at earlier ages than other children (Lodico and DiClemente, 1994; Noll et al., 2003; Springs and Friedrich, 1992; Wilson and Widom, 2008). In addition, there is limited evidence of an association between child abuse and neglect and increased risky sexual behaviors (Jones et al., 2010; Senn et al., 2008). This association has been studied most frequently for sexual abuse; however, Jones and colleagues (2010) found that physical and emotional abuse, but not neglect, contributed to risky behaviors over and above the effects of sexual abuse. Trickett and colleagues (2011) undertook one of the most extensive longitudinal studies of developmental outcomes for female victims of sexual abuse. The majority had experienced severe sexual abuse, defined by the type of abuse (with vaginal and anal penetrative abuse seen as most severe), the length of time over which the abuse occurred, and the relationship of the abuser to the victim. In addition to earlier initiation of sexual activity among women who had been sexually abused in childhood, the authors found less use of birth control (Noll et al., 2003). For both abused and nonabused women, having a large number of male peers in childhood networks was associated with a lack of birth control use in adolescence (Trickett et al., 2011). For abused females, however, having high-quality relationships with male peers and nonpeers in childhood was associated with greater birth control use in adolescence; in the comparison group, this association was not found. Teen PregnancyEvidence linking childhood sexual abuse and increased risk for teen pregnancy has been mixed. Trickett and colleagues (2011) found that severely sexually abused females reported significantly higher rates of teen pregnancy and teen motherhood than nonabused females (abused = 39 percent, nonabused = 15 percent). In a meta-analysis of previously published studies of sequelae of child sexual abuse, Noll and colleagues (2009) found an increased risk for early pregnancy among girls who had been sexually abused. In contrast, using a prospective cohort design that followed children with documented cases of abuse and neglect into young adulthood, Widom and Kuhns (1996) found no evidence that childhood sexual abuse was a significant risk factor for multiple early sexual partners or teenage pregnancy. Prostitution and Risk for Commercial Sexual Exploitation of Children and AdultsIn a prospective study, Widom and Kuhns (1996) found that sexual abuse and neglect, but not physical abuse, were associated with later prostitution. In a subsequent study, Wilson and Widom (2010) examined the role of problem behaviors as a pathway to adult prostitution and found that adult victims who had experienced child abuse and neglect were more likely than nonvictims to report having been involved in prostitution as adults or prostituted as juveniles (Wilson and Widom, 2008). Stoltz and colleagues (2007) found a significant relationship between child abuse and neglect (sexual, physical, and emotional) and later involvement in prostitution among a sample of 361 drug-using, street-involved youth in Canada. While an important topic, evidence that child abuse and neglect increase the risk for commercial sexual exploitation of children is very limited and comes primarily from retrospective studies of sexually exploited youth. Some older studies have reported that experiences of childhood sexual abuse influenced the decision of young women to become involved in commercial sex work (Bagley and Young, 1987; Silbert and Pines, 1983). A comprehensive look at those issues will be presented in a forthcoming Institute of Medicine report from the Committee on Commercial Sexual Exploitation and Sex Trafficking of Minors in the United States.
INDIVIDUAL DIFFERENCES IN OUTCOMESThis chapter has presented extensive evidence that children who are abused or neglected, as a group, are at increased risk for a variety of problematic outcomes. However, not all children who experience abuse or neglect experience these negative consequences. Not surprisingly (given what is known about typical development), children vary in the outcomes they experience even when exposed to the same type of abuse or neglect, with outcomes ranging from the most problematic to functioning well across domains. As discussed earlier in this chapter, an ecological-transactional model is helpful for understanding outcomes related to abuse and neglect as influenced by the interplay of risk and protective factors that occur at multiple levels of a child's ecology. Through examination of compensatory resources in children and their environment, an ecological-transactional framework can aid in understanding children who exhibit resilient outcomes despite having been abused or neglected (Cicchetti and Toth, 2009; Luthar et al., 2000). Factors that influence resilience among abused and neglected children have been identified at the level of the individual child, the family, and the child's broader social context. However, neither a child's individual strengths nor the surrounding environment alone can predict resilient outcomes. As noted by Jaffee and colleagues (2007, p. 233), “the fit between the child and the environment is the best predictor of children's psychological well-being.” The following sections describe research examining explanatory factors for differences in outcomes related to child abuse and neglect. Characteristics of Abuse or Neglect ExperiencesCharacteristics of a child's exposure to abuse or neglect have been shown to influence the risk for problematic outcomes. Such characteristics include the point within the course of a child's development at which an experience of abuse or neglect occurs; the chronicity of abuse or neglect experiences, taking into account their duration and frequency; the severity of the experiences; and the type of abuse or neglect (Bulik et al., 2001; Collishaw et al., 2007; Keiley et al., 2001; Manly et al., 2001). Among a sample of adult female twins, Bulik and colleagues (2001) found an association between characteristics of the abuse experience (e.g., a high level of severity of child sexual abuse, such as attempted or completed intercourse and the use of force or threats) and certain psychiatric disorders. In examining the effect of timing on outcomes related to child physical abuse, Keiley and colleagues (2001) found that children who experienced such abuse while under the age of 5 were at higher risk for negative outcomes than those who experienced the same type of abuse at age 5 or older. Jonson-Reid and colleagues (2012) found that nearly all children who experienced chronic, persisting abusing or neglect showed adverse outcomes in adulthood: 91.9 percent of children showed at least one negative outcome if they had 12 or more reports of abuse or neglect (Jonson-Reid et al., 2012). ResilienceThe concept of resilience serves as a useful lens for evaluating the differing outcomes of children exposed to abuse and neglect. By examining factors that contribute to whether children experience maladaptive outcomes in response to abuse or neglect, researchers can gain a better understanding of how better to prevent and treat these consequences. While resilience has been defined in various ways, it can be understood as “a good outcome in spite of high risk, sustained competence under stress, and recovery from trauma” (McGloin and Widom, 2001, p. 1022). The study of resilience in the context of child abuse and neglect must take into account several factors. First, as shown throughout this chapter, consequences of child abuse and neglect can manifest in multiple domains of functioning. Therefore, a child's subsequent adaptation or maladaptation following abuse or neglect must be assessed in terms of multiple outcomes rather than a single indicator, such as depression (Afifi and Macmillan, 2011; McGloin and Widom, 2001). Second, resilience is not a static construct, meaning that a child can exhibit resilient outcomes at a certain point in the course of development but may still experience problematic outcomes at a later time. It follows that analysis of resilience in abused and neglected children should include a temporal component (McGloin and Widom, 2001). Third, many factors believed to promote resilience in response to child abuse and neglect can also serve to promote positive adaptation more generally in response to other childhood stressors, making it imperative for studies to include a comparison group that has not been abused or neglected (Collishaw et al., 2007). Finally, resilience might usefully be considered from the perspective of allostatic load (Danese and McEwen, 2012). That is, some children who experience abuse or neglect do not show problematic outcomes, but as abuse, neglect, and other adverse childhood experiences accumulate, they challenge children's ability to cope with the negotiation of life tasks. Results from a study of adults who were the subjects of substantiated cases of child abuse or neglect as children indicate that 22 percent of abused and neglected individuals met the criteria for resilience, which required successful functioning in 6 of 8 domains (McGloin and Widom, 2001). A study by Collishaw and colleagues (2007) examined resilience to adult psychopathology within a representative community sample, finding that 44 percent of adults who reported abuse during childhood reported no psychiatric problems in adulthood and demonstrated positive adaptation in other domains. Protective factors supporting resilience have been examined at the levels of the individual, family, and social environment, with resilience being measured in childhood, adolescence, and early adulthood. In a review of protective factors for resilience following child abuse and neglect, Afifi and Macmillan (2011) identify three protective factors that are best supported by findings from longitudinal and cross-sectional studies: a stable family environment, supportive familial relationships, and personality traits that support social skills. Individual-level protective factors identified among those displaying resilience following child abuse and neglect include personality traits (e.g., high ego control, high self-esteem, internal locus of control, external attributions of blame, and attribution of success to own efforts); gender (females more resilient than males); and relationship capabilities (Afifi and Macmillan, 2011; Collishaw et al., 2007; Jaffee and Gallop, 2007; Jaffee et al., 2007). There is some evidence that intelligence or cognitive ability functions as a protective factor (Masten and Tellegen, 2012), but it has not always been found to be significant in supporting resilience (Afifi and Macmillan, 2011; Collishaw et al., 2007). Jaffee and colleagues (2007) found that children with protective individual-level characteristics were likely to be resilient in low-stress environments (59 percent), but children with the same protective individual-level characteristics were less likely to be resilient in highly challenging environments. Family-level protective factors include a caring and safe home environment; positive changes in family structure (e.g., intervention, cessation of visiting rights, or removal to foster care); and supportive familial relationships at the time of abuse (Afifi and Macmillan, 2011; Collishaw et al., 2007; Jaffee et al., 2007). In a sample of sexually abused girls in foster care, family support was not found to be a protective factor, but peer influences, school plan certainty, and positive future orientation were (Edmond et al., 2006). Other social-level protective factors include supportive relationships with non-family members, such as teachers or camp counselors, and supportive relationships with peers in adolescence (Flores et al., 2005; Jaffee et al., 2007). Gene x Environment InteractionsHistorically, those working in the field of child abuse and neglect were unable to examine whether such adverse experiences interacted with biological risk or protective factors (e.g., so-called risk or protective genes)—specifically, whether experience interacted with underlying genetics. This situation has changed over the past 20 years as advances in molecular genetics have enabled a search for gene x environment (GxE) interactions. A number of such interactions have been studied in the last several decades in relation to early adversity generally and child abuse and neglect in particular. Critics of these approaches charge, among other things, that examining single gene and single environment combinations in interactions capitalizes on chance. In addition, some experts in genetics argue that the action of any single gene is likely to be very small, and to detect its effects will likely require very large sample sizes. Nonetheless, some GxE findings have emerged as robust and apparently replicable. The 5-HTT gene is perhaps at the top of this list. This gene regulates reuptake of serotonin (a neurotransmitter that has various functions, including regulation of mood and sleep and some cognitive functions, such as memory and learning) at the synaptic cleft. The gene has long and short allelic variants that confer differential reuptake efficiency. Rodent, nonhuman primate, and human studies (e.g., Caspi et al., 2003) have shown that two alleles confer advantage among animals raised in stressful environments. Caspi and colleagues (2003) found that adults who had experienced stressful life events as children were more likely to have a major depressive disorder if they had one or two short alleles. Those who had two long alleles were no more likely to develop depression than individuals who had not experienced stressful life events. A second genetic polymorphism that has received much attention is a functional polymorphism in the promoter region of the monoamine oxidase A (MAOA) gene. MAOA encodes the MAOA enzyme and selectively degrades serotonin, norepinephrine, and dopamine. Abused and neglected boys with the genotype conferring low levels of MAOA expression were found to be more likely to develop a range of externalizing behaviors, including conduct disorder, antisocial personality disorder, and violent criminality (Caspi et al., 2002). However, subsequent studies have failed to replicate these findings or have demonstrated only partial replications (Huizinga et al., 2006; Widom and Brzustowicz, 2006). For a recent review of the GxE literature concerned with child depression and abuse, see Dunn and colleagues (2011).
ECONOMIC BURDENAlthough the total costs of child abuse and neglect are difficult to gauge because much abuse is unreported (Waters et al., 2004), a number of studies over the last few decades have attempted to document the economic burden of child abuse and neglect on society (Corso and Fertig, 2010; Fang et al., 2012; Wang and Holton, 2007; Waters et al., 2004). Economic burden or economic impact analyses typically quantify burden by aggregating the direct medical expenditures resulting from a condition, the direct nonmedical expenditures associated with a condition, and the subsequent indirect losses in productivity potential for society. These analyses often are called cost of illness/injury analyses. Examples of direct medical expenditures include inpatient and outpatient hospital care, mental health care, medical transport required in the event of an emergency, medications and medical devices, and the medical treatment of chronic conditions resulting from the abuse. Multiple studies since the 1993 NRC report was issued have assessed the direct medical costs associated with child abuse and neglect (Brown et al., 2011), particularly the inpatient costs associated with severe abuse (Courtney, 1999; Evasovich et al., 1998; Irazuzta et al., 1997; Libby et al., 2003; New and Berliner, 2000; Rovi et al., 2004). Direct nonmedical expenditures include use of the child welfare system, law enforcement, and the criminal justice system. Studies have included nonmedical costs in their assessment of the economic burden of child abuse and neglect (Staudt, 2003; Zagar et al., 2009). Productivity losses include the child's missing school or performing at subpar levels in school because of the abuse, parents missing work or performing at subpar levels at work because of the abuse situation or having to deal with child welfare and criminal justice services, and permanent losses in lifetime productivity potential because of premature death. Productivity losses and economic well-being have been incorporated into a number of analyses of the economic burden of child abuse and neglect (Brown et al., 2011; Corso and Fertig, 2010; Corso et al., 2011; Currie and Widom, 2010; Fang et al., 2012). Gelles and Perlman (2012) estimate that cases of abuse or neglect impose a cumulative cost to society of $80.2 billion each year—$33.3 billion in direct costs and $46.9 billion in indirect costs. An analysis by the Centers for Disease Control and Prevention found that the average lifetime cost of a case of nonfatal child abuse and neglect is $210,012 in 2010 dollars, most of this total ($144,360) due to lost productivity but also encompassing the costs of child and adult health care, child welfare, criminal justice, and special education (Fang et al., 2012). The average lifetime cost of a case of fatal child abuse and neglect is $1.27 million, due mainly to loss of productivity. Currie and Widom (2010) found that adults who had experienced abuse and neglect in childhood had lower levels of education, employment, and earnings and fewer assets than adults without a history of abuse and neglect. A higher percentage of adults who had been abused or neglected as children worked in menial, semiskilled positions at age 29 compared with adults who had not been abused or neglected—62 versus 45 percent, respectively. More of the abused and neglected group has been unemployed at some point during the previous 5 years (41 versus 58 percent, respectively). And fewer of those from the abused or neglected group were currently employed or had a bank account, owned a car, or owned their home. Larger effects were seen for women than for men. Analyses of the economic burden of child abuse and neglect could be strengthened by greater transparency in the study methods, including a full accounting of all cost categories that may be impacted by abuse and neglect and transparency in the unit cost estimates for each cost category, as well as a methodologically sound choice of study design for estimating economic burden (Corso and Fertig, 2010; Corso and Lutzker, 2006; Fang et al., 2012). Several approaches could be taken to estimate economic burden, each of which has advantages and disadvantages that could potentially result in overestimating or underestimating the true economic cost of child abuse and neglect. Options include using cross-sectional data to compare the medical costs for an abused/neglected population compared with a nonabused/nonneglected population, including only those health care costs that can be explicitly linked to diagnosis-specific health care utilization (and costs) through the use of diagnosis and external cause codes used in inpatient settings, and supplementing either of these two approaches by including the costs of the fraction of other health conditions attributed to child abuse and neglect.
CONCLUSIONSChild abuse and neglect appear to influence the course of development by altering many elements of biological, cognitive, psychosocial, and behavioral development; in other words, child abuse and neglect “get under the skin” (Hertzman and Boyce, 2010) to have a profound and often lasting impact on development. Brain development is affected, as is the ability to make decisions as carefully as one's peers, or executive functioning; the ability to regulate physiology, behavior, and emotions is impaired; and the trajectory toward more problematic outcomes is impacted. Effects are seen across domains, with the interplay across brain and behavioral systems being particularly striking. Risk and protective factors across multiple levels of a child's ecology interact to influence outcomes related to child abuse and neglect. Factors that influence resilience across these domains are important to an understanding of how to protect children from the adverse outcomes discussed in this chapter. Evidence suggests that the timing, chronicity, and severity of the abuse or neglect matter in terms of outcomes. The more times children experience abuse or neglect, the worse are the outcomes (Jonson-Reid et al., 2012). As Jonson-Reid and colleagues (2012) point out, it is not enough to know whether an event happened; one must also know how ongoing the problem is. The committee sees as hopeful the evidence that changing environments can change brain development, health, and behavioral outcomes. There is a window of opportunity, with developmental tasks becoming increasingly more challenging to negotiate with continued abuse and neglect over time. Future research in this area needs to focus on disentangling the effects of child abuse and neglect from those of other conditions. There is a need to explore beneath the surface to understand the behavioral, neurobiological, social, and environmental mechanisms that mediate the association between exposure to abuse and neglect and their behavioral and neurobiological sequelae. REFERENCES
What occurs during middle adulthood?Middle adulthood, or middle age, is the time of life between ages 40 and 65. During this time, people experience many physical changes that signal that the person is aging, including gray hair and hair loss, wrinkles and age spots, vision and hearing loss, and weight gain, commonly called the middle age spread.
What is middle adulthood quizlet?Middle Adulthood. 40-65 years of age characterized by decline in physical ability, along with exploration, regarding one's "second adulthood." Midlife crisis. Generativity.
Which of the following is considered middle adulthood?Middle adulthood is between ages 40-65 for women and 50 to early 60s for men. This age bracket is known as middle adulthood because it occurs after young adulthood ends but before late adulthood begins.
What defines middle age or middle adulthood?Middle adulthood, or midlife, refers to the period of the lifespan between early adulthood and late adulthood. Although ages and tasks are culturally defined, the most common age definition is from 40-45 to 60-65.
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