SMI Research Digest: Cannabis

SMI Research Digest is a monthly publication from Treatment Advocacy Center (TAC) that summarizes recently published research on topics related to serious mental illness (SMI) with psychosis. This month’s SMI Research Digest focuses on the relationship between cannabis and psychotic disorders.

What is the relationship between cannabis and psychosis?

Exposure to tetrahydrocannabinol (THC), the compound responsible for the “euphoric high” effects of recreational cannabis, can induce psychotic symptoms such as hallucinations and paranoid delusions in some people.

There is sufficient evidence across multiple research studies that cannabis can increase a person’s risk of developing psychosis. This includes a 2020 review of 56 studies, which reported that “frequent cannabis use, especially daily use, and the consumption of high-potency cannabis are associated with a higher risk of developing psychosis.”

Recent research has built on and expanded this knowledge base, including:

• A 2025 study of more than 13.5 million people in Ontario found “the proportion of incident cases of schizophrenia associated with cannabis use disorder almost tripled during a period of substantial liberalization of cannabis policy.”
• A 2025 analysis of data from 10 studies reported, “Cannabinoids likely carry a specific contributing risk for the development of schizophrenia and psychosis-like events in later life, especially when consumed during adolescence. Preventing cannabis use in this life stage may have a large effect on reducing the burden of psychiatric diseases.”
• A 2026 review of 13 studies found that “approximately one in five patients diagnosed with cannabis-induced psychosis will develop schizophrenia spectrum disorder, while one in twenty will be later diagnosed with bipolar disorder.”

While the exact biological mechanisms of this phenomenon are not fully understood, there is evidence pointing to the impact of cannabis on the brain’s dopamine signaling pathways and other neurotransmitter systems.

Does cannabis worsen existing schizophrenia spectrum and other psychotic disorders?

Yes, according to research. Cannabis use is associated with higher rates of relapse, hospitalization, and more severe symptoms in patients with psychotic disorders.

Cannabis is also associated with significantly increased suicide risk for people experiencing their first episode of psychosis. The odds of death by suicide are 2.7 times higher for those who use cannabis daily than for those who do not. Rates are 3.1 times higher for those who use high-potency cannabis.

How can I help reduce the prevalence of cannabis-induced psychotic disorders in my state?

As cannabis use in the United States becomes more widespread and normalized, regulation and public education are needed to mitigate risks associated with high-potency THC.

Advocates looking to make an impact in this area can consider the following actions:

• Pursue legislation to require warning labels. Nicotine and tobacco products carry warning labels to inform consumers about health risks. Similar labels are needed to educate the public about the health risks associated with daily or high-potency THC use.
• Seek limits on THC potency. States vary in the concentration of THC permitted in recreational cannabis products. Learn about regulations in your state and consider adapting policies from other states when advocating for limits on the potency of legally distributed cannabis products.
• Get involved with grassroots groups focused on cannabis. Consider joining the efforts of Johnny’s Ambassadors, Smart Approaches to Marijuana (SAM), and the Parent Action Network to help educate the public on risks associated with cannabis and support legislative and regulatory efforts.

If you want to be an SMI champion, but don’t know the next step to drive policy change in this topic area, our team is happy to help. Connect with us through the form on our website, and we’ll be happy to support your advocacy efforts.