Development and Psychopathology

Many young people who are mistreated by an adult, victimized by bullies, criminally assaulted, or who witness domestic violence react to this violence exposure by developing behavioral, emotional, or learning problems. What is less well known is that adverse experiences like violence exposure can lead to hidden physical alterations inside a child's body, alterations that may have adverse effects on life-long health. We discuss why this is important for the field of developmental psychopathology and for society, and we recommend that stress-biology research and intervention science join forces to tackle the problem. We examine the evidence base in relation to stress-sensitive measures for the body (inflammatory reactions, telomere erosion, epigenetic methylation, and gene expression) and brain (mental disorders, neuroimaging, and neuropsychological testing). We also review promising interventions for families, couples, and children that have been designed to reduce the effects of childhood violence exposure. We invite intervention scientists and stress-biology researchers to collaborate in adding stress-biology measures to randomized clinical trials of interventions intended to reduce effects of violence exposure and other traumas on young people.

Previous studies with nonhuman species have shown that animals exposed to early adversity show differential DNA methylation relative to comparison animals. The current study examined differential methylation among 14 children raised since birth in institutional care and 14 comparison children raised by their biological parents. Blood samples were taken from children in middle childhood. Analysis of whole-genome methylation patterns was performed using the Infinium HumanMethylation27 BeadChip assay (Illumina), which contains 27,578 CpG sites, covering approximately 14,000 gene promoters. Group differences were registered, which were characterized primarily by greater methylation in the institutionalized group relative to the comparison group, with most of these differences in genes involved in the control of immune response and cellular signaling systems, including a number of crucial players important for neural communication and brain development and functioning. The findings suggest that patterns of differential methylation seen in nonhuman species with altered maternal care are also characteristic of children who experience early maternal separation.

Các quá trình tự điều chỉnh được cho là rất quan trọng cho sự điều chỉnh tính cách và hành vi ở giai đoạn đầu. Những quá trình này có thể được quan sát ở nhiều cấp độ, bao gồm cả các lĩnh vực chức năng sinh lý, chú ý, cảm xúc, nhận thức và giữa các cá nhân. Dữ liệu từ một số nghiên cứu theo chiều dọc cho thấy có mối liên hệ giữa những khuynh hướng tính cách sớm như sự ngăn chặn hành vi và khả năng chịu đựng sự thất vọng, và sự phát triển điều chỉnh ở các cấp độ điều tiết sinh lý, sự chú ý và điều tiết cảm xúc. Những thiếu sót ở các cấp độ tự điều chỉnh này có thể dẫn đến sự rút lui xã hội và hành vi hung hãn ở trẻ em. Còn tồn tại nhiều khoảng trống đáng kể trong hiểu biết của chúng ta về các con đường dẫn đến hành vi rối loạn và vai trò mà tự điều chỉnh đóng trong những con đường đó. Đề xuất được đưa ra cho các phương pháp mà các nghiên cứu theo chiều dọc trong tương lai có thể tiếp cận những khoảng trống này.

This article reviews and reflects on studies that have explored the effects of war on children around the world. Most are cross-sectional and based on self-reports. They describe a range of mental health problems, related to dose effects and to the negative impact of being a victim or witness of violent acts, threats to and loss of loved ones, prolonged parental absence, and forced displacement. The more recent the exposure to war, and the older the child, the higher was the likelihood of reported posttraumatic stress disorder symptoms. Especially vulnerable to long-term emotional distress were child soldiers, children who were raped, and children who had been forcibly displaced. In adulthood, war-traumatized children displayed significantly increased risks for a wide range of medical conditions, especially cardiovascular diseases. Among protective factors that moderated the impact of war-related adversities in children were a strong bond between the primary caregiver and the child, the social support of teachers and peers, and a shared sense of values. Among the few documented intervention studies for children of war, school-based interventions, implemented by teachers or locally trained paraprofessionals, proved to be a feasible and low-cost alternative to individual or group therapy. More longitudinal research with multiple informants is needed to document the trajectories of risk and resilience in war-affected children, to assess their long-term development and mental health, and to identify effective treatment approaches.

Child abuse is associated with markedly elevated rates of major depression (MDD) in child, adolescent, and adult cohorts. This article reviews preclinical (e.g., animal) studies of the effects of early stress and studies of the neurobiological correlates of MDD in adults and children, and it highlights differences in the neurobiological correlates of MDD and stress at various developmental stages. The preclinical studies demonstrate that stress early in life can alter the development multiple neurotransmitter systems and promote structural and functional alterations in brain regions similar to those seen in adults with depression. Preclinical and clinical studies suggest, however, that long-term neurobiological changes associated with early stress can be modified by familial/genetic factors, the quality of the subsequent caregiving environment, and pharmacological interventions. Little is known about how developmental factors interact with experiences of early stress and these other modifying factors. Moreover, in cases of child maltreatment, the effects of early abuse are often exacerbated by failures in the child protection system and repeat out-of-home placements. Given the number of factors that impact on the long-term outcome of maltreated children, multidisciplinary research efforts are recommended to address this problem—with foci that span from neurobiology to social policy.

Increasing evidence supports the view that the interaction of perinatal exposure to adversity with individual genetic liabilities may increase an individual's vulnerability to the expression of psycho- and physiopathology throughout life. The early environment appears to program some aspects of neurobiological development and, in turn, behavioral, emotional, cognitive, and physiological development. Several rodent and primate models of early adverse experience have been analyzed in this review, including those that “model” maternal separation or loss, abuse or neglect, and social deprivation. Accumulating evidence shows that these early traumatic experiences are associated with long-term alterations in coping style, emotional and behavioral regulation, neuroendocrine responsiveness to stress, social “fitness,” cognitive function, brain morphology, neurochemistry, and expression levels of central nervous system genes that have been related to anxiety and mood disorders. Studies are underway to identify important aspects of adverse early experience, such as (a) the existence of “sensitive periods” during development associated with alterations in particular output systems, (b) the presence of “windows of opportunity” during which targeted interventions (e.g., nurturant parenting or supportive–enriching environment) may prevent or reverse dysfunction, (c) the identity of gene polymorphisms contributing to the individual's variability in vulnerability, and (d) a means to translate the timing of these developmental “sensitive periods” across species.

Internal representations of self and primary attachment figures may be one mechanism by which maltreatment affects children's interpersonal behavior and relationships with others. Research on the continuity and influence of maltreated children's attachment representations, however, has not included youngsters removed from abusive or neglectful home environments. This paper examines the influence of maltreated children's maternal and self-representations on subsequent relationships with foster mothers and behavioral adjustment in foster care. Participants included 32 children, ages 9–13 years, who entered foster placement for the first time after a sustained relationship with a maltreating biological mother. Upon initially entering foster care, children's maternal and self-representations were significantly related to each other and to severity of maltreatment history but not to other factors believed to influence the quality of parent–child relationship (e.g., maternal mental health, partner stability). In addition, these representations significantly predicted children's subsequent views of their relationships with foster mothers. Finally, children's behavior in their foster homes was associated with maltreatment severity, internal representations assessed at entry into foster care, and to concurrent perceptions of their new foster mothers. These findings advance our understanding of foster placement's role in maltreated children's development and provide preliminary insight into the processes associated with the formation of potentially compensatory relationships.