Mental health and quality of life in a population of recreative cannabis users in Brazil

Cannabis is the third most used recreational drug worldwide. Despite the popularity of cannabis use among Brazilians, information about frequent cannabis users outside clinical contexts remains scarce. This is a cross-sectional study of a non-probabilistic sample of 7405 Brazilian adults (6620 [89.4%] cannabis users and 785 [10.6%] non-users) who answered an online survey that collected demographic data, cannabis and other substance use information (initial substance use, lifetime and past-month use), and standardized scales to assess quality of life, subjective well-being, anxiety, and depression scores. Among cannabis users, 17.1% of the participants self-classified themselves as occasional users, 64.6% as habitual users, and 7.7% as dysfunctional users. Participants were mostly young male adults, with at least high-school education, employed, without children. The highest scores for quality of life were observed among habitual cannabis users, followed by occasional users, while both non-users and dysfunctional users presented less favorable scores. Subjective measures of well-being were higher among habitual and occasional users than among non-users, whereas dysfunctional users were the most affected. Poor quality of life, depression or anxiety were more prevalent among dysfunctional users, but non-users of cannabis reported more depression or anxiety symptoms and less quality of life than both occasional and habitual users. The results obtained in this study are particularly relevant because they refer to a sample predominantly composed of habitual cannabis users from the general population, a rarely represented group in other surveys. The fact that cannabis use is generally associated with increased risk of adverse health outcomes was not observed in this study.