Cannabis use patterns and different phenotypes in relation to other drugs use: latent class analyses from the Sao Paulo Megacity Mental Health Survey.

Abstract

Cannabis is the most widely used substance in Brazil. This study examined subtypes of individuals who use cannabis based on usage characteristics and correlates with other substance consumption and harms. Data are from the São Paulo Megacity Mental Health Survey (N = 5,037). Latent class analysis (LCA) was performed considering age of onset, use frequency , tobacco consumption, heavy episodic drinking (HED), alcohol use disorder (AUD) and substance use disorder. Logistic regression assessed class correlates, and further analysis compared socio-demographic, health and behavioral indicators. A 4-class model was optimal for 496 individuals. The 'Polydrug' class (26.2%) and the 'Former' class (5.9%) showed earlier onset and highest frequency of cannabis use, with strongest harm associations. 'Polydrug' class had higher odds of other drug use (OR=3.0), tobacco use (OR=2.5), HED (OR=1.8), and AUD (OR=1.5), compared to lighter-use groups. About 30% of those who use cannabis are at increased risk for negative outcomes, particularly those with early, frequent, and polydrug use patterns. Brazil's public health should prioritize targeted prevention on the risks associated with early and frequent cannabis, and polydrug use. Addressing this at-risk group is essential for harm reduction and a health-focused approach.