A longitudinal, sibling-comparison study of trauma exposure during adolescence and trajectories of externalizing problems through young adulthood.

Childhood maltreatment has been implicated in adulthood externalizing behaviors. However, this relationship could be explained by confounding factors (e.g., externalizing risk factors that co-occur with childhood maltreatment), rather than a direct effect of maltreatment on externalizing behavior. The current study extends this research using a longitudinal sibling study. Specifically, we leveraged the sibling-comparison design, which compares siblings from the same family to each other to examine whether greater maltreatment exposure at baseline (M age = 16.9) is associated with greater increases in externalizing behavior through young adulthood (M age = 29.1). Thus, this approach controls for familial risk factors shared by siblings. Participants included 365 probands and 376 siblings who were followed across three assessment waves. Participants were administered clinical interviews at each wave to assess alcohol use disorder (AUD), illicit substance use disorder (SUD), and antisocial behavior (ASB), and a self-report survey of exposure to physical abuse, emotional abuse, sexual abuse, and neglect. Greater adolescent exposure to neglect and physical abuse were both associated with greater adolescent levels of AUD and ASB. Adolescent physical abuse, but not neglect, was also associated with greater illicit SUD symptoms. Additionally, greater emotional abuse was associated with steeper increases in AUD and illicit SUD symptoms through young adulthood. Importantly, none of these effects were explained by familial confounds. These findings provide strong evidence for adolescent emotional abuse playing a causal role in later AUD/SUD, suggesting that preventing such abuse and mitigating its effects may have downstream effects on reducing AUD/SUD.