This is a proposal to conduct a five-year primary prevention field experiment to reduce drug and alcohol abuse among children of parents enrolled in a non-profit methadone maintenance program. Our prevention research is based on the premise that to be effective, prevention programs should address risk factors specific to the behaviors targeted. Family factors appear particularly salient in the etiology of adolescent drug abuse, and several other precursors of adolescent drug abuse are affected by family environments. Currently, major primary prevention efforts are focused on school based programs (NIDA, 1987). Fewer prevention experiments have focused on families despite their implication in etiology and the fact that parent training has demonstrated effectiveness in reducing risk factors for adolescent drug abuse. The experimental parent program to be tested has several unique aspects. First, all subjects are drawn from a high risk population, children of methadone maintenance parents, in which family factors implicated in the etiology of drug abuse are particularly adverse. Second, research suggests that high risk families require twice as many hours of training compared to parents from the general population, and the proposed parent training program will provide more hours of training than many general population parent programs (60 hours over 19 weeks plus seven months of aftercare). In addition, case management (provided to half the experimental subjects) will continue for 19 weeks after parent training is completed. Third, by addressing some of the risk factors for adolescent drug abuse, parent training and case management services are likely to reduce parents' risk for relapse as well. Fourth, the parent training and case management program proposed is theory-based, drawn from the social development model of substance abuse, and the curriculum and case management procedures will be adapted from field tested curriculum which as demonstrated effects on risk and relapse factors.