The influence of adverse childhood experiences on internalizing and externalizing problems in early adulthood: Evidence of a gene × environment × sex interaction

Background Although adverse childhood experiences (ACEs) have negative effects on subsequent wellbeing, questions remain regarding how and why they do so. Sex, environmental effects, and genetic influences may play a role in both one’s exposure to ACEs as well as one’s reactions to ACEs. Objective To understand the combined genetic and environmental influences on males’ and females’ exposure and reactions to ACEs, and to determine whether sex differences in offending and depressive symptoms were partially impacted by genetic influences. Methods We employed a sample of monozygotic twins (n = 217 pairs), same-sex dizygotic twins (n = 185 pairs), and same-sex full siblings (n = 446 pairs) from the National Longitudinal Study of Adolescent to Adult Health (N = 848 pairs) and estimated a series of multivariable biometric models. Participants were aged between 12 and 21 during Wave I, between 13 and 22 at Wave II, between 18 and 26 at Wave III, and 24 and 32 at Wave IV. Results First, there appears to be a stronger genetic influence on ACEs exposure among males than females. Second, genetic influences were stronger on offending among males and depression among females. Third, ACEs moderate the genetic influences on offending and depressive symptomology among males and females: among males, genetic influences on offending decreased as exposure to ACEs increased, while among females, genetic influences on depressive symptoms decreased as exposure to ACEs increased. Conclusions Systematic sex differences in the exposure and reactions to ACEs are at least partially due to genetic differences. Exposure to ACEs is partially influenced by genetics among males, but not females, and the more male and females’ experience ACEs, the less influence genes have on their offending and depressive symptomology, respectively