Monthly simultaneous cannabis and alcohol use: effects on depression, anxiety, and stress in male and female college students

Alcohol and cannabis are two of the most commonly used and co-used substances by young adults, and simultaneous cannabis and alcohol (SCA) use has been linked to increased risk for negative consequences, including poor mental health. College students represent an important group to study given their high prevalence of co-use and rising rates of depression, anxiety, and stress. Further, sex-related differences have been observed in polysubstance use, and research is needed on how SCA use may be differentially related to mental health outcomes in male and female college students. This cross-sectional survey study on N = 367 college students compared male and female sexes on the relationships between monthly SCA use (compared to less than monthly) and depression, anxiety, and stress. A multigroup path analysis was conducted to simultaneously regress mental health symptoms onto a dichotomously coded SCA group variable, while controlling for age, most recent cannabis use, and typical alcohol frequency, with sex as the grouping variable. A post-hoc Monte Carlo simulation was conducted to examine power and provide recommendations for sample sizes in future research. Monthly SCA use significantly positively predicted depression in male (β = 0.322) and female (β = 0.296) college students, and the relation between SCA and depression was not different between sexes (p = 0.939). While anxiety (β = 0.323) and stress (β = 0.369) were significantly positively predicted by monthly SCA use in males, but not females, the relations between SCA and anxiety, as well as stress, were not significantly different between the sexes. Across sexes, more frequent SCA use is positively associated with depression symptoms in college students. Although SCA use was also linked to higher anxiety and stress among males but not females, these sex differences were not significant. Studies with greater statistical power are warranted to investigate potential sex differences.