Emergency department use by individuals with and without psychosis after state-level cannabis legalization and commercialization
A. Hyatt, M. Flores, Lindsay N. Overhage, Danta Bien-Aime, A. Evins, D. Öngür, Benjamin Le Cook
Nature Mental Health June 19, 2026 DOI: 10.1038/s44220-026-00673-x (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Longitudinal cohort study using difference-in-difference analysis Peer reviewed |
|---|---|
| Population | Individuals with psychosis compared with the general population without a history of psychosis, drawn from a nationally representative survey in the USA |
| Duration | 3 years of follow-up; data collection 2013–2022 |
| Topics | Cannabis |
| Key findings | The opening of cannabis retail outlets was associated with an increase in emergency department visits among individuals with psychosis (0.43 more visits per person per year) but not among those without a history of psychosis. The authors report this as early evidence and argue for policy collaboration to minimize harms among people with serious mental illness. |
Abstract
Recreational cannabis legalization and commercialization are expanding rapidly in the USA, with potential negative effects for individuals with psychotic disorders. Here, to assess potential health risks associated with the opening of cannabis retail outlets, we conducted a longitudinal cohort study using a nationally representative survey to evaluate trends in emergency department utilization among individuals with psychosis compared with the general population with 3 years of follow-up. Data collection occurred in 2013–2022. Utilizing difference-in-difference (DiD) methods, we found that the opening of cannabis retail outlets was associated with an overall increase in emergency department visits among individuals with psychosis in legalization states (DiD estimate of 0.43 more visits per-person per-year, 95% CI −0.014 to 0.85, P = 0.043) but not among those with no history of psychosis (DiD estimate −0.015, 95% CI −0.03 to 0.06, P = 0.54). Exploratory analyses found this change was driven by more emergency department utilization among individuals with psychosis and past-year cannabis use, and not among other subgroups. This provides early evidence that cannabis commercialization is associated with worsening health among individuals with psychosis, and indicates a need for researchers, regulators and policymakers to collaborate to develop policies to minimize harms of cannabis legalization and commercialization among individuals with serious mental illnesses. The opening of cannabis retail outlets in the USA was associated with an overall increase in emergency department visits among individuals with psychosis but not among those with no history of psychosis.