A new review in Jama Internal Medicine takes a hard look at how cannabis affects mental health. The authors note that while many people believe that cannabis helps their mental health, current evidence of its suggested benefits is weak while evidence of harm, especially with high THC products, is substantial. This is particularly important considering reasons for use include symptom management.

This review found insufficient evidence to support cannabis as a treatment for PTSD, ADHD, anxiety, or depression. Studies included in this review found that high THC worsens anxiety and may trigger depressive episodes as well as suicidality in young people and psychotic symptoms, with repeated use raising the risk of chronic psychotic disorders, especially in adolescence. In one of the studies, an 11-fold increase of risk of psychosis was found.

The review pointed out that about 30% of people who reported past-year cannabis use met the criteria for cannabis use disorder (CUD), and about half of those cases were moderate to severe. CUD was linked to higher risk of self-harm and unintentional opioid overdose. Continued use can also lead to Cannabis Induced Psychosis (CIP) as well as verbal, working memory, and executive function deficits. CIP can be an early indicator for the development of schizophrenia in nearly half of chronic psychotic cases, with adolescent cannabis exposure further increasing these risks. CIP can serve as an early marker of progression toward schizophrenia in nearly half of chronic psychotic cases, and these risks appear to be further elevated among individuals exposed to cannabis during adolescence.

The increase in THC potency and the worrisome trend of increase in use presents a threat to those who are already at risk or have a lower perception of harm such as adolescents, young adults, pregnant individuals, people with bipolar disorders, people with psychotic disorders or have a family history of psychotic disorders. Regular cannabis use can worsen mania, other mental health outcomes, and reduce recovery from bipolar disorder.

In some studies of this review, adverse reactions between CBD, THC, and mental health medications were observed. It is important to note that the U.S. Food and Drug Administration has not approved the use of cannabis for pharmacological treatment.

The authors of this review recommend routine screening of cannabis use, including non-judgmental approaches when asking patients about cannabis use. These discussions should include potency, frequency of use, and education around synthetic cannabinoids as these lead to greater risk of harm. It is also important to educate patients about drug interactions, and the possibility of cannabis use worsening health outcomes.

To learn more about the impacts of high potency marijuana on mental health, download Drug Free America Foundation’s resource here.

References

Kansagara, D., Terry, GE., Ayers, CK., D’Souza, DC. (2026). Cannabis and Mental Health: A Review. JAMA Internal Medicine. Advance Online Publication. doi:10.1001/jamainternmed.2025.8215