Families and risk: prospective analyses of familial and social influences on adolescent substance use.

Parental, peer, and older siblings' contributions to adolescents' substance use were investigated with 2 waves of panel data from 225 African American families. Structural equation modeling showed that older siblings' behavioral willingness (BW) to use substances at Time 1 (T1) predicted target adolescents' Time 2 (T2) use, controlling for other T1 variables. Regression analyses revealed an interaction between targets' and siblings' BW, such that targets were more likely to use at T2 if both they and their siblings reported BW at T1. This interaction was stronger for families living in high-risk neighborhoods. Finally, siblings' willingness buffered the impact of peer use on targets' later use: Low sibling BW was associated with less evidence of peer influence.