Rates and correlates of cannabis-associated psychotic symptoms in over 230,000 people who use cannabis
Tabea Schoeler, Jason Ferris, Adam Winstock
Translational Psychiatry September 6, 2022 DOI: 10.1038/s41398-022-02112-8 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 233,475 |
| Population | International sample of people who use cannabis (PWUC) |
| Topics | Anxiety Cannabis |
| Keywords | Context archaeology Paranoia Depression economics Psychosis Relative risk Confidence interval |
| Citations | 48 |
| Key findings | 0.47% of people who use cannabis reported lifetime occurrence of acute cannabis-associated psychotic symptoms requiring emergency medical treatment, with substantially higher risk among young individuals, those in Denmark, users of high-potency resin, those mixing cannabis with tobacco, and those with pre-existing mental health diagnoses. |
Abstract
Cannabis, a widely used psychoactive substance, can trigger acute cannabis-associated psychotic symptoms (CAPS) in people who use cannabis (PWUC). To assess rates and correlates of CAPS requiring emergency medical treatment, we analyzed data from an international sample of PWUC (n = 233,475). We found that 0.47% (95%CI 0.42; 0.52) PWUC reported lifetime occurrence of CAPS, defined as the occurrence of hallucinations and/or paranoia requiring emergency medical treatment following the use of cannabis. A range of factors correlated with risk of CAPS in the last year: higher rates were observed in young individuals [risk ratio (RR) 2.66, compared to older PWUC] and those residing in Denmark (RR 3.01, compared to PWUC from other countries). Furthermore, risk was elevated in those using predominantly high-potency resin (RR 2.11, compared to PWUC using herbal cannabis), those mixing cannabis with tobacco (RR 2.15, compared to PWUC not mixing with tobacco) and those with a diagnosis of psychosis (RR 14.01), bipolar (RR 4.30), anxiety (RR 2.92) and depression (RR 2.68), compared to individuals without a mental health diagnosis. Taken together, acute self-limiting psychotic symptoms in the context of cannabis use may occur in about 1 in 200 PWUC's lifetime. Some individuals could be particularly sensitive to the adverse psychological effects of cannabis, such as young individuals or those with pre-existing mental health vulnerabilities. In light of the movements towards legalization of recreational cannabis, more research should focus on the potential harms related to cannabis use, to educate PWUC and the public about risks related to its use.
In the evidence
This study is part of the evidence base for a synthesis in the library. Here is how each one recorded it.
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People with a pre-existing anxiety diagnosis had higher risk of cannabis-associated psychotic symptoms requiring emergency treatment (risk ratio 2.92).
Synthesized
Comparable studies
Other observational and cohort studies on cannabis for anxiety, most cited first.
Citations in the library
Cited by 10
- Sociodemographic differences and experienced effects of young adults who use cannabis mainly for self-medication versus recreationally in Finland Drugs, Habits and Social Policy August 18, 2023
- Evaluating the value and risks of psychedelics for psychiatric medicine: a clinical perspective. Expert Review of Neurotherapeutics February 1, 2025
- The Cannabis-Psychosis Spectrum: Clinical Manifestations, Conversion Risk, and Therapeutic Strategies Clinical Neuropsychopharmacology and Addiction August 6, 2025
- Cannabis use and glutamate across the psychosis spectrum: in vivo evidence from 7T proton magnetic resonance spectroscopy Molecular Psychiatry June 27, 2026
- Introducing the ASI-NPI project: preliminary analysis of a study exploring the role of cannabis, salience alterations and youth in determining psychotic symptoms severity Research Square November 20, 2023
and 5 more in the library
Cites 25
- Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment Journal of Psychopharmacology October 5, 2012
- Traditional marijuana, high‐potency cannabis and synthetic cannabinoids: increasing risk for psychosis World Psychiatry September 22, 2016
- Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases The British Journal of Psychiatry November 30, 2005
- Are adolescents more vulnerable to the harmful effects of cannabis than adults? A placebo-controlled study in human males Translational Psychiatry November 29, 2016
- Acute memory and psychotomimetic effects of cannabis and tobacco both ‘joint’ and individually: a placebo-controlled trial Psychological Medicine May 30, 2017
and 20 more in the library