Family and peer predictors of substance use from early adolescence to early adulthood: an 11-year prospective analysis.

The focus of this study was social (i.e., family and peer) influences on substance use from early adolescence to early adulthood. A large, ethnically diverse sample of early adolescents (N=998) was followed from age 12 to age 23. We tested direct and indirect effects of parental monitoring, family relationship quality, and association with deviant peers on change in substance use across time. Outcomes for tobacco, alcohol, and marijuana use were analyzed as separate pathways within the same overall model. The results suggest that a significant shift in the nature of family influence occurred across adolescence and into early adulthood, but deviant peer influence was relatively consistent across this period. Specifically, parental monitoring and deviant peer association were predictive of substance use in early adolescence, but family relationship quality was a significant predictor across the transition to high school and generally continued to predict use into later adolescence, as did association with deviant peers. Deviant peers were the only significant predictor in early adulthood. Our results also suggested that parental monitoring and family relationship quality indirectly predicted later substance use by way of deviant peers, implying that an important aspect of the family context is its influence on choice of friends and peer group composition. Implications for family-based prevention and intervention are discussed.