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Tuesday, Sep. 2, 2025

Is there evidence linking marijuana use to psychosis?

Tom Kertscher / Wisconsin Watch, Wisconsin Watch
yes

Peer-reviewed research found links between marijuana use and psychosis – the loss of contact with reality, experienced as delusions or hallucinations.

The consensus is there is a clear association, but more research is needed to determine if  there is causation.

That’s according to the Journal of Cannabis Research editor, researchers at the Institute of Cannabis Research and a review of 32 studies that reviewed research. 

The institute’s Jeff Smith said most cannabis users don’t develop psychosis.

Research samples:

Lifetime use is associated with increased odds of psychosis, especially among daily or weekly users. 

Psychotic disorders are 11 times more likely among adolescent users than non-users.

Republican U.S. Rep. Tom Tiffany, who represents most of northern Wisconsin, called for more research on the link to inform legalization policy. 

Marijuana for recreational use is legal in 24 states. In May, Republicans nixed a Wisconsin legalization proposal.

This fact brief is responsive to conversations such as this one.

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