Information was collected on family structure; conflict between the parents; maternal depressive mood; dynamics of the interactions between the youths and their mothers; and the young adults' alcohol use, alcohol-related behaviors, and use of marijuana and other drugs. All of the 49 male and 54 female adolescents were white. Their ages ranged from 12.8 to 17.0 years and averaged 15.0 years. Seventy-two had parents with intact marriages; 31 were living with their mothers and had parents who were divorced 1-3 years before the initial assessment. Results revealed that higher levels of conflict between the parents were consistently related to poorer quality of the mother-adolescent relationship and stricter maternal control. Overall, the dynamics of the mother-adolescent relationship served both direct and mediating roles in the prediction of males' and females' drug use. However, findings also revealed notable differences between the trajectories of males and females, as well as between different types of drug use. Figures, tables, and 67 references