The Effects of Parent, Sibling and Peer Substance Use on Adolescent Drinking Behaviors

Understanding influences and predictors of adolescent alcohol use is necessary for treatment and prevention efforts. Although parent, sibling, and peer substance use have demonstrated associations with adolescent drinking, there is a need to examine the unique predictive role of each variable across time. The purpose of the current study was to longitudinally examine the varying influences of parent, sibling, and peer substance use on adolescent drinking. Participants were 102 at-risk adolescents referred to a randomized intervention trial. Hierarchical multiple regressions were conducted to assess the utility of parent alcohol use, sibling alcohol use, and peer substance use to predict drinking outcomes in the referred adolescent at 3-, 6-, and 12-month follow-up assessments. Results indicated that sibling and peer substance use significantly predicted adolescent drinking frequency above and beyond parent alcohol use at all three time points and drinking quantity and frequency of intoxication at the 12-month follow-up. Peer substance use predicted high volume drinking episodes at all follow-ups and frequency of intoxication at the 3- and 6-month follow-up, whereas only sibling alcohol use predicted drinking quantity at the 3-month follow-up. Parent alcohol use was not a significant predictor of drinking outcomes at any time point. Both sibling and peer substance use were better predictors of adolescent drinking typology at different assessment time points compared to parent alcohol use. These findings highlight the importance of assessing and targeting sibling and peer substance use in intervention and prevention programs.