Cannabis Legalization Linked to Increased Psychosis Severity
Publication Title: Changes in cannabis use following legalization: Effects in first-episode psychosis
Summary
- Question
- This study examined how the legalization of recreational cannabis in Connecticut impacted cannabis use patterns among individuals experiencing first-episode psychosis (FEP). Specifically, the researchers aimed to assess changes in the severity and frequency of cannabis use before and after legalization.
- Why it Matters
Cannabis use is known to worsen outcomes in individuals with FEP, such as increasing the risk of relapse, hospitalization, and social difficulties. Understanding how legalization affects cannabis use in these patients is crucial for designing public health strategies and early intervention programs. This research offers insights into how legal and societal changes may influence substance use behaviors in individuals with severe mental health conditions.
- Methods
- The researchers analyzed data from individuals aged 16 to 35 enrolled in a community-based early intervention program for FEP in Connecticut between 2014 and 2025. Participants were grouped into pre-legalization (213 individuals) and post-legalization (129 individuals) cohorts. Cannabis use was assessed using structured interviews, which measured the frequency, context, and severity of use over the previous six months. Participants were categorized as abstinent, mild users, or moderate-to-severe users.
- Key Findings
- Following cannabis legalization, the proportion of individuals with moderate-to-severe cannabis use increased from 35.2% to 52.8%, while the proportion of abstinent individuals decreased from 46% to 30%. Among current cannabis users, daily use rose from 56.2% to 67.5%, and solitary use increased from 19% to 30.7%, though these changes were not statistically significant. There was no change in the age of first cannabis use.
- Implications
- The findings suggest that cannabis legalization may contribute to more severe patterns of use among individuals with FEP, potentially exacerbating their mental health challenges. The rise in daily and solitary use could indicate an increased risk of cannabis dependence and related complications in this population. These results underscore the need for targeted public health interventions to address cannabis use in individuals with early psychosis.
- Next Steps
The authors recommend continued monitoring of cannabis use patterns in individuals with FEP, particularly as cannabis commercialization progresses in Connecticut. Future research should examine the impact of higher-potency cannabis products and explore strategies to mitigate risks associated with increased cannabis availability in this population.
- Funding Information
- This research was supported by the Gustavus and Louise Pfeiffer Research Foundation. Additional funding was provided by the State of Connecticut Department of Mental Health and Addiction Services (DMHAS) and the Department of Children and Families (DCF), though this publication does not express the views of these Departments or the State of Connecticut. Yale University also provided funding and support for this research.
Full Citation
Authors
Deepa Purushothaman
First AuthorVinod H. Srihari, MD
Last AuthorProfessor of Psychiatry