The effects of family, school, peers, and attitudes on adolescents' drug use: Do they vary with age?

This study tested developmental hypotheses, derived from Thornberry's interactional theory, about the age-varying effects of attachment to parents, commitment to school, association with drug-using peers, and pro-drug attitudes on adolescents' drug use. Multilevel modeling was applied to test the hypotheses by analyzing data from the National Youth Survey. First, as hypothesized, school and peer influence begins to increase from early adolescence, peaks during middle adolescence, and declines thereafter. Second, the hypothesized patterns of the age-varying effects of family (decreasing) and pro-drug attitudes (increasing) fail to receive empirical support, but their effects are found to follow a curvilinear, rather than a linear, pattern.