Family environment moderates the impact of genetic propensity on internalizing and externalizing behaviors during late childhood and adolescence

AbstractBackgroundFamily environment plays an important role in the development of mental health problems in late childhood and adolescence. Environmental processes such as parenting practices and family conflict have been identified as moderating genetic propensity for the development of both externalizing and internalizing psychopathology during these developmental periods using twin models. However, we still do not understand how individual processes within the family environment uniquely impact the development of externalizing and internalizing problems while also accounting for measured genetic risk. In the current study we sought to characterize how these environmental processes, along with genetic risk, relate uniquely to externalizing and internalizing outcomes at two developmental stages, ages 10 and 14. MethodsThe analytic sample (N=10,633) was drawn from the Adolescent Brain Cognitive Development (ABCD) Study. We examined associations between eight family variables, reflecting parental mental health, parenting, and family environment, and externalizing and internalizing polygenic scores (PGS) as well as externalizing and internalizing behaviors. We also tested for moderation of the PGS by the family variables in predicting externalizing and internalizing behaviors. Linear mixed effects models were run cross-sectionally at ages 10 and 14 with random effects of family.ResultsFamily variables were associated with the EXT and INT PGS as well as externalizing and internalizing behaviors at both ages. The EXT and INT PGS were associated with externalizing and internalizing behaviors at both ages. Parental substance use problems, family conflict, and parental knowledge significantly moderated associations between the EXT PGS and externalizing behaviors. There were no significant moderation effects with the INT PGS.ConclusionsFamily processes are robustly associated with externalizing and internalizing behaviors and moderate the impact of genetic influences on the development of externalizing psychopathology. These effects were largely consistent in late childhood and adolescence.