The participants all met the DSM-III-R criteria for either drug abuse or drug dependence related to at least one psychoactive substance. The youths completed the Personal Experience Inventory of Winders and Henly. Multiple regression analyses used psychosocial risk variables to predict drug use frequency in the prior 12 months. The study tested the hypothesis that the delinquency factor would account for the most variance in drug use, compared to three competing factors: psychological distress, nonconventional values, and family distress. Results provided support for the hypothesis across gender, age, and ethnic groups. The delinquency factor uniquely accounted for about 50-60 percent of the variance in drug use severity. Backward deletion regression analysis of individual scales indicated that peer chemical environment and deviant behavior (both part of the delinquency block) and, to a lesser degree, psychological disturbance (part of the psychological distress block) were consistently most predictive of drug use. Findings were consistent with the opinion that delinquency behaviors are important mediators of adolescent drug abuse and thus that they deserve central attention in prevention programs. Findings also indicated a continuing need to develop and test theories about the pathways to drug involvement pertinent to severe-end, clinic-referred adolescents. Tables and 31 references (Author abstract modified)