Drug abuse among adolescents is a pressing health concern with serious consequences for individual youth and for society as a whole. Although the magnitude of the problem has stimulated a dramatic increase in research attention in recent years, the field of adolescent substance abuse has been characterized by an absence of controlled clinical trials of drug abuse intervention program, and few effective, replicable, and enduring treatment strategies have been identified. Self-regulation models, which aim to enable adolescents to identify appropriate behavioral goals and use self-regulation skills such as stimulus control and contingency reinforcement to prompt desirable behaviors, have been used successfully for drug abuse prevention, but research on treatment programs for adolescents abusers has been rare. Similarly, family treatments increasingly have been advocated. Many family therapists argue that drug abuse develops and is maintained in the context of maladaptive family relationships and that correcting faulty family interaction patterns will, in turn, reduce adolescents' involvement with drugs. Despite considerable enthusiasm which has been generated for these approaches, however, few studies have systematically investigated the effectiveness of family therapy with substance abusers. The proposed clinical trial for adolescent drug abusers will examine treatment outcomes for two contrasting intervention approaches, individual self-regulation skills training and family therapy. The effectiveness of these interventions will be compared with an education-based group intervention. The self-regulation training and family therapy approaches will also be offered in combination in a fourth condition, to evaluate the additive treatment effects for adolescents and their families. Together, an evaluation of outcomes across the four conditions will provide a clearer understanding of which approaches to treatment have greatest benefit at the level of the individual drug abuser, the abusers' parents and siblings, and the family system functioning. The project will also allow for an examination of treatment-matching variables to address whether some adolescents respond better to one type of treatment than another. Outcome research, however, is often limited by insufficient attention to therapy process variables related to successful outcomes. To address this issue, the proposed trial will also examine client and therapist characteristics and treatment operations which may influence treatment outcome.