# Cannabis use and psychosis onset research

> Live situation record from CLSTR: https://clstr.news/situations/cannabis-use-and-psychosis-onset-research
> Updated: 2026-08-26T09:30:00.000Z. Sources: 10. Developments: 3.

A meta-analysis published in Biological Psychiatry by researchers at the University of New South Wales has linked cannabis use to an earlier onset of psychosis. The study, which reviewed 149 international studies involving more than 71,000 participants, found that cannabis users developed psychosis an average of approximately two and a half years earlier than non-users.

The research indicates that the age of onset significantly influences this gap. For those experiencing their first episode between ages 20 and 24, the onset was roughly 1.6 years earlier. This difference increased to 4.43 years for individuals between ages 25 and 29, and reached a maximum of 6.3 years for those developing the disorder after age 30. Researchers noted that while the correlation was notable in older age groups, they did not find a statistically significant difference in timing among adolescents compared to non-users.

Co-authors Matthew Large and Carly Stevens noted that the findings challenge the misconception that waiting until the mid-20s to use cannabis mitigates these risks. Researchers suggested the risk may be tied to cumulative toxicity and years of exposure, drawing a comparison to the long-term impact of tobacco on lung cancer.

## Timeline

### 2026-08-26: Study links early cannabis use to earlier onset of psychosis

A large-scale study published in Biological Psychiatry links early cannabis use to an earlier onset of psychosis and increased risks of mental illness, particularly in younger users.

3 sources. https://clstr.news/cluster/study-links-early-cannabis-use-to-earlier-onset-of-psychosis

### 2026-08-19: Medical studies link diet and cannabis use to health risks

Medical studies link high ultra-processed food consumption to a 30% higher prostate cancer risk in men and connect cannabis use to an earlier onset of psychotic symptoms.

3 sources. https://clstr.news/cluster/medical-studies-link-diet-and-cannabis-use-to-health-risks

### 2026-08-18: Cannabis use linked to earlier onset of psychosis, study finds

A meta-analysis of 71,000 participants shows cannabis use is linked to earlier psychosis onset, with the age gap reaching up to 6.3 years for those developing symptoms after age 30.

4 sources. https://clstr.news/cluster/cannabis-use-in-20s-and-30s-linked-to-earlier-psychosis-onset

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Cite as: Cannabis use and psychosis onset research. CLSTR, https://clstr.news/situations/cannabis-use-and-psychosis-onset-research