Cannabis use and sexual risk among MSM who drink: Understanding why more frequent cannabis users may engage in higher rates of condomless sex

Background: Condomless anal intercourse (CAI) is the major risk factor for HIV transmission among men who have sex with men (MSM). MSM who are heavier cannabis users engage in CAI more frequently. However, little is known about the processes that may underlie this association. This study sought to understand the potential role of condom attitudes and condom-related planning in the association between cannabis use and CAI. Methods: This is a secondary data analysis of a study on alcohol use and sexual decision-making among MSM. Two hundred and fifty-eight MSM with moderate to heavy drinking were enrolled. Measures included CAI, cannabis use, attitudes about the influence of condoms on sexual pleasure, condom use planning, age, heavy episodic drinking, and use of pre-exposure prophylaxis (PrEP). Results: We conducted a negative binomial regression analysis controlling for age, PrEP, and heavy episodic drinking. Cannabis use frequency was a significant predictor of CAI (b =.333, p < .001). Indirect effects showed that while heavier cannabis users exhibited less condom-related planning (b = −0.106, p = 0.015) and more negative attitudes toward the impact of condom use on pleasure (b= −0.177, p = 0.004), cannabis use had a significant indirect effect on CAI only through attitude ratings. Conclusions: MSM who are heavier cannabis users engage in more frequent CAI and exhibit an indirect effect on CAI through negative attitudes toward the impact of condoms on pleasure. These findings suggest the potential importance of addressing these condom attitudes in HIV-prevention interventions among MSM who use cannabis.