About 30% of Cannabis Users in São Paulo Showed High-Risk Use Patterns
Latent class analysis of 496 cannabis users in São Paulo identified four distinct user profiles, with about 30% in high-risk categories marked by early onset, frequent use, and polydrug patterns.
Quick Facts
What This Study Found
A four-class model identified distinct cannabis user profiles: a Polydrug class (26.2%) and a Former class (5.9%) with earlier onset and highest frequency, and two lighter-use groups. The Polydrug class had higher odds of other drug use (OR 3.0), tobacco (OR 2.5), heavy episodic drinking (OR 1.8), and alcohol use disorder (OR 1.5).
Key Numbers
5,037 total survey participants. 496 cannabis users analyzed. Four classes identified. Polydrug class (26.2%): OR 3.0 for other drugs, OR 2.5 tobacco, OR 1.8 heavy drinking, OR 1.5 AUD. Former class (5.9%): earliest onset and highest historical frequency. About 30% at increased risk.
How They Did This
Data from the São Paulo Megacity Mental Health Survey (n=5,037). Latent class analysis of 496 cannabis users based on age of onset, use frequency, tobacco consumption, heavy episodic drinking, alcohol use disorder, and substance use disorder. Logistic regression assessed correlates.
Why This Research Matters
Not all cannabis users face the same risks. Identifying distinct user profiles helps target prevention and harm reduction efforts toward the subset of users who are most vulnerable to negative outcomes.
The Bigger Picture
This population-level classification study from Brazil adds to the global evidence that cannabis use is not monolithic. A minority of users account for a disproportionate share of harm, a pattern consistent with findings from other countries.
What This Study Doesn't Tell Us
Cross-sectional design limits causal inference. Self-reported substance use. São Paulo sample may not represent all of Brazil. Latent class analysis findings are sample-dependent and may not replicate in other populations.
Questions This Raises
- ?Can the high-risk classes be identified early enough for prevention?
- ?Would these same classes emerge in different cultural contexts?
Trust & Context
- Key Stat:
- Evidence Grade:
- Population-based survey with sophisticated statistical methodology, but cross-sectional design and single-city sampling limit evidence to moderate.
- Study Age:
- Data from the São Paulo Megacity Mental Health Survey.
- Original Title:
- Cannabis use patterns and different phenotypes in relation to other drugs use: latent class analyses from the Sao Paulo Megacity Mental Health Survey.
- Published In:
- Revista brasileira de psiquiatria (Sao Paulo, Brazil : 1999), 47, e20243833 (2025)
- Authors:
- Silveira, Camila Magalhães, Castaldelli-Maia, João Maurício(2), Siu, Erica Rosanna, Viana, Maria Carmen, Wang, Yuan-Pang, Andrade, Laura Helena
- Database ID:
- RTHC-07659
Evidence Hierarchy
Watches what happens naturally without intervening.
What do these levels mean? →Frequently Asked Questions
What defines high-risk cannabis use?
In this study, the high-risk profiles were characterized by earlier age of onset, more frequent use, and concurrent use of other substances including tobacco, alcohol, and other drugs.
Are most cannabis users at high risk?
No. About 70% of cannabis users in this study fell into lower-risk categories. The 30% in higher-risk groups accounted for most of the associated harms.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-07659APA
Silveira, Camila Magalhães; Castaldelli-Maia, João Maurício; Siu, Erica Rosanna; Viana, Maria Carmen; Wang, Yuan-Pang; Andrade, Laura Helena. (2025). Cannabis use patterns and different phenotypes in relation to other drugs use: latent class analyses from the Sao Paulo Megacity Mental Health Survey.. Revista brasileira de psiquiatria (Sao Paulo, Brazil : 1999), 47, e20243833. https://doi.org/10.47626/1516-4446-2024-3833
MLA
Silveira, Camila Magalhães, et al. "Cannabis use patterns and different phenotypes in relation to other drugs use: latent class analyses from the Sao Paulo Megacity Mental Health Survey.." Revista brasileira de psiquiatria (Sao Paulo, 2025. https://doi.org/10.47626/1516-4446-2024-3833
RethinkTHC
RethinkTHC Research Database. "Cannabis use patterns and different phenotypes in relation t..." RTHC-07659. Retrieved from https://rethinkthc.com/research/silveira-2025-cannabis-use-patterns-and
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.