962Adolescent Alcohol Use Trajectories: A Prospective Study of Risk Factors and Adulthood AUD Outcomes

Background Adolescents often display heterogenous trajectories of alcohol use. Initiation and escalation of drinking may be an important predictor of later harms. Previous attempts to conceptualise these trajectories lacked adjustment for known confounders of adolescent drinking, which our study has aimed to address by modelling dynamic changes in drinking whilst adjusting for parent, child, and peer factors. Methods Survey data from a longitudinal cohort of Australian adolescents (n = 1813) were used to model latent class alcohol use trajectories over five annual follow-ups (Mage=13.9 and 17.8 years). Regression models determined whether child, parent, and peer factors at baseline (Mage =12.9 years) predicted trajectory membership and whether trajectories predicted self-reported symptoms of AUD in early adulthood (Mage =18.8 years). Results We identified a four-class solution: abstaining (n = 352); late-onset moderate drinking (n = 503); early-onset moderate drinking (n = 663); and early-onset heavy drinking (n = 295). Alcohol-specific household rules reduced risk of early-onset heavy drinking compared to late-onset moderate drinking (RRR: 0.31; 99.5% CI: 0.11, 0.83), whereas substance-using peers increased this risk (RRR: 3.43; 99.5% CI: 2.10, 5.62). Early-onset heavy drinking increased odds of meeting criteria for AUD in early adulthood (OR: 7.68; 99.5% CI: 2.41, 24.47). Conclusions Our study provides evidence that early initiation and heavy alcohol use throughout adolescence is associated with increased risk of alcohol-related harm compared to recommended maximum levels of consumption (late-onset, moderate drinking). Key messages Parenting factors and peer influences in early adolescence should be considered to reduce risk of early initiation and heavy drinking, which in turn reduces risk of later harm.

Latent trajectories of alcohol use from early adolescence to young adulthood: Interaction effects between 5-HTTLPR and parenting quality and gender differences

Using a large and nationally representative sample, we examined how adolescents’ 5-HTTLPR genotype and perceived parenting quality independently and interactively associated with trajectories of alcohol use from early adolescence to young adulthood and whether/how gender may moderate these associations. The sample for this study included 13,749 adolescents (53.3% female; 56.3% non-Hispanic White, 21.5% Black, 16.0% Hispanic, and 6.1% Asian) followed prospectively from adolescence to young adulthood. Using growth mixture modeling, we identified four distinct trajectories of alcohol use (i.e., persistent heavy alcohol use, developmentally limited alcohol use, late-onset heavy alcohol use, and non/light alcohol use). Results indicated that the short allele of 5-HTTLPR was associated with higher risk of membership in the persistent and the late-onset heavy alcohol use trajectories. Parenting quality was associated with lower likelihoods of following the persistent heavy and the developmentally limited alcohol use trajectories but was not associated with risk of membership for the late-onset heavy drinking trajectory. 5-HTTLPR interacted with parenting quality to predict membership in the persistent heavy alcohol use trajectory for males but not for females. Findings highlighted the importance of considering the heterogeneity in trajectories of alcohol use across development and gender in the study of Gene Environment interactions in alcohol use.