Cannabis users with psychotic disorders reported significantly more adverse events — including nausea/vomiting, cardiovascular problems, fainting, and CHS — than users with other mental health conditions or none.
Psychiatrists, mental health clinicians, cannabis dispensary staff, and people with psychotic disorders considering cannabis use
What the researchers found
People with psychotic disorders were more likely than those with other MH or no MH diagnoses to report adverse events from cannabis (p<.001), including nausea/vomiting, heart/blood pressure problems, fainting, acute psychosis, flashbacks, CHS, and high-risk cannabis use screening positive.
Why it matters
Cannabis harm isn't equally distributed — people with psychotic disorders are disproportionately vulnerable, experiencing more adverse events even beyond the expected psychiatric worsening.
The numbers in context
4,144 Washington State cannabis consumers; ages 16-65; 2020-2023; psychotic disorder group significantly more likely to report adverse events and seek medical attention (p<.001) across multiple outcome categories.
How the study worked
Cross-sectional analysis of 4,144 past-year cannabis consumers in Washington State from the International Cannabis Policy Study (2020-2023), comparing adverse events across psychotic disorder, other MH, and no MH diagnosis groups.
What this study cannot tell us
Self-reported diagnoses and adverse events; cross-sectional design; Washington State only; cannot determine if adverse events are caused by cannabis or reflect underlying disorder severity.
How to read the evidence
Multi-year population study with appropriate comparison groups, but self-reported data and cross-sectional design limit causal inference.
When this study was published
Published in 2026 with 2020-2023 data from a mature legal cannabis market.
The bigger picture
The finding that psychotic disorder patients experience more non-psychiatric adverse events (cardiovascular, GI) from cannabis suggests broader physiological vulnerability, not just psychiatric exacerbation.
Questions still open
- Should cannabis dispensaries screen for psychotic disorders? Is there a safe way for people with psychotic disorders to use cannabis, or should it be contraindicated?
Common questions
Is cannabis more dangerous for people with psychosis?
What adverse events do people with psychotic disorders experience from cannabis?
Read the original research
People with psychotic disorders are the most vulnerable to cannabis adverse health outcomes: a study in WA State, USA.
Community mental health journal
Citation
Carlini, Beatriz H; Williams, Jason R; Garrett, Sharon B; Hammond, David. (2026). People with psychotic disorders are the most vulnerable to cannabis adverse health outcomes: a study in WA State, USA.. Community mental health journal. https://doi.org/10.1007/s10597-025-01579-1
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