Previous studies have identified an association between depressive mood and marijuana use. We examined adolescent self-control as a predictor of membership in joint developmental trajectories of depressive mood and marijuana use from adolescence to young adulthood. Urban African Americans and Puerto Ricans (N = 838) were sampled when participants were on average 14, 19, 24, and 29 years old. Using growth mixture modeling, four joint trajectory groups of depressive mood and marijuana use were established: low marijuana use/low depressive mood, low marijuana use/intermediate depressive mood, high marijuana use/low depressive mood, and high marijuana use/high depressive mood. Weighted logistic regression analysis showed that self-control at age 14 distinguished the high marijuana use/high depressive mood group and the low marijuana use/low depressive mood group from each of the other groups. Findings show that the co-occurrence of high levels of marijuana use and depressive mood from adolescence into young adulthood is predicted by low levels of self-control in adolescence. On the other hand, high selfcontrol is associated with low marijuana use and low levels of depression over time. Thus, while deficits in self-control in adolescence constitute a significant risk for maladjustment over time, high self-control exerts a protective factor with regard to marijuana use and depressive mood into young adulthood.
