Adolescents undergoing rapid and sometimes confusing developmental changes are especially vulnerable to substance abuse and related problems. Only by dealing with the primary network of significant others who surround and influence children and youth can effective, long-range solutions be implemented. Issues discussed include: (1) the extent and cost of adolescent drug use and the institutionalized forces that entice youngsters to use drugs; (2) patterns of family interaction that contribute to adolescent drug initiation, reinforcement, and maintenance; (3) family structure and parent-youth interaction; and (4) the developmental stages of drug involvement and the changing family circumstances at each stage. Also discussed are the influence of ethnicity in affecting adolescent substance use, developmental approaches to adolescent drug use, youngsters with learning disabilities, and the empirical guidelines for designing and evaluating interventions aimed at adolescents who are at risk or already drug involved. 500 references and 3 notes.