Please use this link to access this publication. Abstract 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...