Negative mood as a mediator of the association between insomnia severity and marijuana problems in college students

Insomnia symptoms have been linked to problematic marijuana use among young adults, but the mechanism underlying this association and whether sex differences exist, remains unclear. Using cross-sectional data, this study examined negative mood as a mediator of the association between insomnia and marijuana problems among male and female college students. Undergraduate students (n = 267; 61% female) reporting marijuana use in the past month completed an online survey assessing insomnia symptoms, negative mood and marijuana problems. Controlling for relevant covariates, negative mood was examined as a mediator of the association between insomnia and marijuana problems using bootstrapped significance tests for indirect effects (n-boot = 1,000). Results indicated that higher levels of insomnia were associated with greater levels of negative mood (regardless of sex), which in turn were associated with greater marijuana-related problems. In conclusion, insomnia symptoms are associated with more negative mood among college students who use marijuana, and this effect on negative mood accounts for a large part of the association of insomnia symptoms with marijuana-related problems. Research is needed to determine if these associations are maintained prospectively.