People with Psychosis Show Large Increases in Cannabis Use After Legalization
Individuals with a history of psychosis increased their cannabis use by nearly 10 percentage points after recreational legalization — a larger increase than the general population — raising serious concerns about legalization's impact on mental health.
Quick Facts
What This Study Found
Individuals with psychosis in recreational cannabis legalization states increased 30-day cannabis use by 9.53 percentage points (95% CI=3.05-16.00, p=0.004), with sensitivity analyses showing significant increases after retail outlets opened but not before, and no changes in higher-frequency use.
Key Numbers
N=1,856 with psychosis; 7,465 responses; mean age 36.6; 31.8% baseline 30-day use; 9.53 pp increase post-RCL (p=0.004); significant after retail opening; no change in higher-frequency use; larger than general population estimates
How They Did This
Difference-in-differences analysis using 2014-2022 Population Assessment of Tobacco and Health longitudinal data from 1,856 adults with lifetime psychosis history (7,465 responses), comparing cannabis use changes in RCL vs. control states.
Why This Research Matters
Cannabis can worsen psychosis outcomes, increase hospitalizations, and complicate treatment — yet this vulnerable population shows the largest increase in use after legalization, suggesting current policies inadequately protect high-risk individuals.
The Bigger Picture
This finding challenges the assumption that legalization primarily affects casual users — the largest per-population increase is among those most vulnerable to cannabis harms, demanding targeted policy responses.
What This Study Doesn't Tell Us
Self-reported psychosis history may include misclassification; cannot determine what types of cannabis were used; 30-day use measure doesn't capture daily patterns; sample size limits subgroup analysis; cannot determine if increased use worsened outcomes.
Questions This Raises
- ?Should cannabis regulations include specific protections for people with psychotic disorders?
- ?Would health warnings about psychosis risk reduce use in this group?
- ?Does the type of cannabis product matter for psychosis outcomes?
Trust & Context
- Key Stat:
- Evidence Grade:
- Rigorous quasi-experimental design with nationally representative longitudinal data and consistent sensitivity analyses, providing strong evidence for this concerning association.
- Study Age:
- Published 2026 in JAMA Psychiatry; covers 2014-2022.
- Original Title:
- Cannabis Use Among Individuals With Psychosis After State-Level Commercial Cannabis Legalization.
- Published In:
- JAMA psychiatry, 83(1), 74-77 (2026)
- Authors:
- Hyatt, Andrew S(2), Flores, Michael William, Johnson, Julie, Bien-Aime, Danta, Evins, A Eden, Öngür, Dost, Cook, Benjamin Lê
- Database ID:
- RTHC-08348
Evidence Hierarchy
Frequently Asked Questions
Does cannabis legalization affect people with mental illness?
Yes — this study found that people with a history of psychosis increased their cannabis use by nearly 10 percentage points after legalization, more than the general population, with the increase tied specifically to when retail stores opened.
Why is cannabis use concerning for people with psychosis?
Cannabis can worsen psychotic symptoms, increase relapse rates, and lead to more hospitalizations. The fact that this vulnerable population shows the largest legalization-related increase in use suggests policies need specific protections for high-risk groups.
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Cite This Study
https://rethinkthc.com/research/RTHC-08348APA
Hyatt, Andrew S; Flores, Michael William; Johnson, Julie; Bien-Aime, Danta; Evins, A Eden; Öngür, Dost; Cook, Benjamin Lê. (2026). Cannabis Use Among Individuals With Psychosis After State-Level Commercial Cannabis Legalization.. JAMA psychiatry, 83(1), 74-77. https://doi.org/10.1001/jamapsychiatry.2025.2539
MLA
Hyatt, Andrew S, et al. "Cannabis Use Among Individuals With Psychosis After State-Level Commercial Cannabis Legalization.." JAMA psychiatry, 2026. https://doi.org/10.1001/jamapsychiatry.2025.2539
RethinkTHC
RethinkTHC Research Database. "Cannabis Use Among Individuals With Psychosis After State-Le..." RTHC-08348. Retrieved from https://rethinkthc.com/research/hyatt-2026-cannabis-use-among-individuals
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.