Adolescent alcohol use trajectories: risk factors and adult outcomes

OBJECTIVES: Adolescents often display heterogenous trajectories of alcohol use. Initiation and abstractescalation of drinking may be important predictors of later harms, including alcohol usedisorder (AUD). Previous conceptualizations of these trajectories lacked adjustment forknown confounders of adolescent drinking, which we aimed to address by modeling dynamicchanges in drinking throughout adolescence while adjusting for covariates.METHODS: Survey data from a longitudinal cohort of Australian adolescents (n = 1813) were usedto model latent class alcohol use trajectories over 5 annual follow-ups (mean age = 13.9 until17.8 years). Regression models were used to determine whether child, parent, and peerfactors at baseline (mean age = 12.9 years) predicted trajectory membership and whethertrajectories predicted self-reported symptoms of AUD at the final follow-up (mean age = 18.8years).RESULTS: We identified 4 classes: abstaining (n = 352); late-onset moderate drinking (n = 503);early-onset moderate drinking (n = 663); and early-onset heavy drinking (n = 295). Havingmore alcohol-specific household rules reduced risk of early-onset heavy drinking comparedwith late-onset moderate drinking (relative risk ratio: 0.31; 99.5% confidence interval [CI]:0.11–0.83), whereas having more substance-using peers increased this risk (relative risk ratio:3.43; 99.5% CI: 2.10–5.62). Early-onset heavy drinking increased odds of meeting criteria forAUD in early adulthood (odds ratio: 7.68; 99.5% CI: 2.41–24.47).CONCLUSIONS: Our study provides evidence that parenting factors and peer influences in earlyadolescence should be considered to reduce risk of later alcohol-related harm. Early initiationand heavy alcohol use throughout adolescence are associated with increased risk of alcoholrelated harm compared with recommended maximum levels of consumption (late-onset,moderate drinking)