A longitudinal, sibling-comparison study of alcohol use disorder and co-occurring internalizing problems across adolescence and young adulthood

AbstractBackground: Internalizing disorders frequently co-occur with alcohol use disorder (AUD) and impede alcohol recovery, but directionality among these disorders is unclear. Further, shared risk factors may explain the co-occurrence of these disorders, rather than either disorder directly affecting the other. Additionally, there is evidence that these disorders are differentially associated in men and women. Method: The current study examined a sample of clinical probands, recruited during adolescence based on externalizing problems, and their siblings to understand whether adolescent alcohol behavior is associated with changes in anxiety and depressive symptoms through young adulthood, and vice-versa. Participants were 1,161 individuals who completed a clinical interview in adolescence (M age=16.3) and at two subsequent waves (M age=22.6 and 28.5). Latent growth curve models tested whether baseline levels behavior (e.g., AUD) is associated with linear change in internalizing problems (e.g., depression) through young adulthood. Further, sibling-comparison analyses were conducted to control familial risk factors shared by siblings while testing whether siblings who have higher levels an independent variable (e.g., adolescent AUD) have proportionally greater increases in an outcome (e.g., depression), relative to their siblings with lower levels of that independent variable. Results: Adolescent AUD was associated with steeper increases in major depressive symptoms through young adulthood, and these effects were not explained by familial confounds. Additionally, adolescent AUD was associated with more adolescent generalized anxiety symptoms in females but less generalized anxiety symptoms among males. Conclusions: These findings suggest that treating early-life AUD may decrease risk for depressive symptoms later in life, but the inverse may not be true.