The Origins of Cognitive Deficits in Victimized Children: Implications for Neuroscientists and Clinicians

Abstract

OBJECTIVE Individuals reporting a history of childhood violence victimization have impaired brain function. However, the clinical significance, reproducibility, and causality of these findings are disputed. We directly tested these research gaps. METHOD We tested the association between prospectively-collected measures of childhood violence victimization and cognitive functions in childhood, adolescence, and adulthood among 2,232 members of the UK E-Risk Study and 1,037 members of the New Zealand Dunedin Study, who were followed-up from birth until ages 18 and 38 years, respectively. We used multiple measures of victimization and cognition, and included comparisons of cognitive scores for twins discordant for victimization. RESULTS We found that individuals exposed to childhood victimization had pervasive impairments in clinically-relevant cognitive functions including general intelligence, executive function, processing speed, memory, perceptual reasoning, and verbal comprehension in adolescence and adulthood. However, the observed cognitive deficits in victimized individuals were largely explained by cognitive deficits that predated childhood victimization and by confounding genetic and environmental risks. CONCLUSIONS Findings from two population-representative birth cohorts totaling more than 3,000 individuals and born 20 years and 20,000 kilometers apart suggest that the association between childhood violence victimization and later cognition is largely non-causal, in contrast to conventional interpretations. These findings urge adopting a more circumspect approach to causal inference in the neuroscience of stress. Clinically, cognitive deficits should be conceptualized as individual risk factors for victimization as well as potential complicating features during treatment.

Childhood and Adolescent Adversity and Cardiometabolic Outcomes: A Scientific Statement From the American Heart Association

“…The possibility of time-varying confounding, that the behaviors and risk factors that are subsequently affected by exposure to childhood adversity may also increase the risk of adversity, is a major threat to causal inference. For example, findings in a genetically informative British cohort indicated that child characteristics such as intelligence quotient and adjustment problems predicted exposure to maltreatment by adults 140 and chronic peer victimization (bullying). 141 Others have shown the adverse effects of maltreatment and peer victimization on child adjustment.…”

Analysis of DNA Methylation in Young People: Limited Evidence for an Association Between Victimization Stress and Epigenetic Variation in Blood

“…Childhood and adolescent victimization experiences in this cohort have been described previously (2, 25) and are summarized here (details are provided in the online data supplement). …”

“…Early-life stress is thought to cause many adverse health outcomes, including altered brain development (1), compromised cognitive functioning (2), poor mental health (3), and multiple physical illnesses (4). Perhaps the most pressing question at the nexus of neurobiology and public health is how stress “gets under the skin” to bring about these pleiotropic effects (5–9).…”

Annual Research Review: Rethinking childhood trauma‐new research directions for measurement, study design and analytical strategies

“…This test is necessary because inconsistencies between animal and human research may arise for several reasons, including differences in life history and brain development timing across species, greater individual differences in human versus animal studies, or routine compensatory interventions (e.g. schooling, child protection services) in human studies (Clancy, Finlay, Darlington, & Anand, ; Danese et al, ; van der Worp et al, ).…”