Pathways linking marijuana use to substance use problems among emerging adults: A prospective analysis of young Black men

Objectives: Marijuana use rates peak during emerging adulthood (ages 18 to 25 years). Although marijuana use quantity reliably predicts substance-related problems, considerable individual differences characterize this association. The aims of the present study were to examine the influence of community disadvantage in amplifying the effects of marijuana use on downstream substance use problems, as well as the mediating influence of social disengagement in the path linking marijuana use frequency to related problems. Method: We conducted a 3-year longitudinal study with 505 Black men from rural communities in Georgia, age 20.3 years at baseline. Three waves of data were collected at 18-month intervals in participants' homes or convenient community settings. Men completed audio computer-assisted self-interviews concerning their substance use, engagement in conventional roles and relationships, community characteristics, and substance use problems. Results: Community disadvantage moderated the association of marijuana use with changes in substance use problems across time. In disadvantaged communities, a robust effect emerged between marijuana use frequency and related problems, whereas in less disadvantaged communities, marijuana use quantity and problems were not significantly associated. Increases in social disengagement mediated the influence of marijuana use on substance use problems in the context of community disadvantage. Conclusions: For young Black men, residence in a disadvantaged neighborhood appears to amplify the impact of marijuana use on substance use problems. This effect appears to be a consequence of increases in social disengagement.