Vita.This paper examines the reciprocal relationship of adolescent drug use and psychological distress, with a special focus on the self-medication hypothesis. The hypothesis suggests that people use drugs to relieve the stress associated with social interaction. The use of drugs, then, is seen as an attempt to "self-medicate" the psychological distress that a person experiences. The analysis uses structural equation modeling to examine this relationship and finds that psychological distress has an indirect effect on later drug use (via disposition to deviance and association with deviant peers), but no direct or indirect effect on later psychological distress (net of concurrent non-drug deviant behavior). The effect of psychological distress on later drug use is moderated by gender and coping processes. Thus, females, those with less effective coping skills, who feel in control of their life and are willing to make changes are more likely to use drugs to self-medicate