A longitudinal analysis of cannabis use and mental health symptoms among gay, bisexual, and other men who have sex with men in Vancouver, Canada

BackgroundCannabis use, anxiety, and depression are common among gay, bisexual, and other men who have sex with men (gbMSM) and some report using cannabis to manage mental health symptoms.MethodsSexually-active gbMSM aged ≥16 years were recruited into a longitudinal cohort through respondent-driven sampling and completed study visits every six months. Data on demographics, drug use, and anxiety and depression symptoms were collected via a self-administered computer-based survey. A study nurse determined previous mental health diagnoses and treatment. Using multivariable generalized linear mixed models, we examined factors associated with regular cannabis use (≥weekly in the previous 3 months) and, among individuals who reported anxiety or depression/bipolar diagnoses, factors associated with moderate/severe anxiety or depression symptoms.ResultsOf 774 participants (551 HIV-negative, 223 HIV-seropositive), 250 (32.3%) reported regular cannabis use, 200 (26.4%) reported ever being diagnosed with anxiety, and 299 (39.3%) reported ever being diagnosed with depression or bipolar disorder at baseline. Regular cannabis use was positively associated with HIV-seropositivity (aOR = 2.23, 95%CI:1.40–3.54) and previous mental health diagnosis (aOR = 1.52, 95%CI: 1.00–2.31, p = 0.05). Among those previously diagnosed with anxiety or depression/bipolar disorder, regular cannabis use was not associated with moderate/severe anxiety (aOR = 1.16, 95%CI:0.69–1.94) or depression symptoms (aOR = 0.96, 95%CI:0.59–1.58), respectively.LimitationsBecause of observational study design, we are unable to determine absolute effect.ConclusionsRegular cannabis use was more likely among HIV-positive gbMSM and those previously diagnosed with a mental health disorder. No association was found between regular cannabis use and severity of anxious or depressive symptoms among those diagnosed with these conditions