Early-life adversity (ELA) encompasses a wide range of experiences and exposures, including physical and sexual abuse, violence, neglect, and institutional rearing. It has been estimated that approximately half of all adolescents in the United States have reported at least 1 lifetime ELA.¹ Extensive research has found that ELA is associated with alterations in psychological, cognitive, and neurobiological development. Meta-analyses consistently show an association between ELA and conditions such as anxiety, depression, attention-deficit/hyperactivity disorder, conduct disorder, suicidality, and substance use disorder.^1-14 Evidence suggests that such associations may be mediated by neurocognitive development.^15-20 For example, ELA may encumber the development of key neurocognitive processes, which, in turn, may increase the risk of psychopathology.^15-20 However, a source of ambiguity in the field of childhood adversity is that research often models ELA using the cumulative risk approach (ie, the sum of adversities experienced) but pays minimal attention to the differential risk conferred by different types of ELA. As a result, associations between particular types of ELA and specific neurocognitive processes that mechanistically connect ELA with mental health may go undetected.²¹ In this systematic review and meta-analysis, we directly addressed this gap in the literature by examining the association between the type of ELA and executive functioning in children and youth.

Emerging evidence suggests that partially distinct mechanisms may underlie the association between different dimensions of early life adversity (ELA) and psychopathology in children and adolescents. While there is minimal evidence that different types of ELA are associated with specific psychopathology outcomes, there are partially unique cognitive and socioemotional consequences of specific dimensions of ELA that increase transdiagnostic risk of mental health problems across the internalizing and externalizing spectra. The current review provides an overview of recent findings examining the cognitive (e.g., language, executive function), socioemotional (e.g., attention bias, emotion regulation), and mental health correlates of ELA along the dimensions of threat/harshness, deprivation, and unpredictability. We underscore similarities and differences in the mechanisms connecting different dimensions of ELA to particular mental health outcomes, and identify gaps and future directions that may help to clarify inconsistencies in the literature. This review focuses on childhood and adolescence, periods of exquisite neurobiological change and sensitivity to the environment. The utility of dimensional models of ELA in better understanding the mechanistic pathways towards the expression of psychopathology is discussed, with the review supporting the value of such models in better understanding the developmental sequelae associated with ELA. Integration of dimensional models of ELA with existing models focused on psychiatric classification and biobehavioral mechanisms may advance our understanding of the etiology, phenomenology, and treatment of mental health difficulties in children and youth.

Background: Children reared in institutions experience profound deprivation that is associated with both heightened levels of psychopathology and deficits in executive functioning (EF). It is unclear whether deficits in EF among institutionally-reared children serve as a vulnerability factor that increases risk for later psychopathology. It is also unclear whether this putative association between EF and psychopathology is transdiagnostic (i.e. cuts across domains of psychopathology), or specific to a given syndrome. Thus, we examined whether global deficits in EF mediate the association between severe childhood neglect and general v. specific psychopathology in adolescence.Methods: The sample consisted of 188 children from the Bucharest Early Intervention Project, a longitudinal study examining the brain and behavioral development of children reared in Romanian institutions and a comparison group of never-institutionalized children. EF was assessed at age 8, 12, and 16 using a well-validated measure of neuropsychological functioning. Psychopathology was measured as general (P) and specific internalizing (INT) and externalizing (EXT) factors at age 12 and 16.Results: Institutionally-reared children had lower global EF and higher general psychopathology (P) at all ages compared to never-institutionalized children. Longitudinal path analysis revealed that the effect of institutionalization on P at age 16 operated indirectly through poorer EF from ages 8 to 12. No indirect effects involving EF were observed for INT or EXT at age 16.Conclusions: We conclude that stable, global deficits in EF serve as a cognitive endophenotype that increases transdiagnostic vulnerability to psychopathology in adolescence among those who have experienced profound early neglect.

Childhood adversity may sensitize certain individuals to later stress which triggers or amplifies psychopathology. The current study uses data from a longitudinal randomized controlled trial to examine whether severe early neglect among children reared in institutions increases vulnerability to the effects of later stressful life events on externalizing problems in adolescence, and whether social enrichment in the form of high-quality foster care buffers this risk. Children abandoned to Romanian institutions were randomly assigned to a foster care intervention or care-as-usual during early childhood. A sample of never-institutionalized children served as a comparison group. Here we report that, among those with prolonged institutional rearing, more stressful life events in preadolescence predicted higher externalizing problems in adolescence. This effect was not observed for never-institutionalized children or those in foster care, thus providing experimental evidence that positive caregiving experiences protect against the stress-sensitizing effects of childhood neglect on externalizing problems in adolescence.