Cannabis and Mental Health: A Review.
Devan Kansagara, Garth E Terry, Chelsea K Ayers, Deepak C D'Souza
JAMA Internal Medicine May 1, 2026 DOI: 10.1001/jamainternmed.2025.8215 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Review Peer reviewed |
|---|---|
| Interventions | Cannabis Δ-9-tetrahydrocannabinol (THC)-predominant cannabis cannabidiol |
| Topics | Cannabis |
| Key findings | The authors conclude that current evidence is insufficient to support cannabis as treatment for mental health conditions and shows substantial adverse effects. They argue cannabis should be avoided by those at elevated risk, including adolescents and young adults, people with bipolar or psychotic disorders, pregnant individuals, and those at risk for substance use disorders, and that clinicians should discuss cannabis use with patients. |
Abstract
Cannabis use is common among those with mental health conditions, and many people report using cannabis to manage mental health symptoms. It is important for clinicians to understand the lack of clear benefits of cannabis for mental health conditions and the potential for substantial adverse effects. Overall, the potential benefits of cannabis for mental health conditions remain poorly studied. There is low-certainty evidence that Δ-9-tetrahydrocannabinol (THC)-predominant cannabis may not improve symptoms of posttraumatic stress disorder, and there is largely insufficient evidence to characterize the effects of long-term THC-predominant cannabis use on anxiety, depression, and attention-deficit/hyperactivity disorder. There is emerging low-certainty evidence that the cannabis constituent cannabidiol alone may reduce anxiety in patients with anxiety disorders. THC-predominant cannabis use holds substantial risk for adverse mental health effects, and counseling patients about these risks is crucial to promote safety. These risks include worsening mania symptoms and function in those with bipolar disorder and an increase in psychotic symptoms in those with psychotic spectrum disorders. Among people with past-year cannabis use, about 3 in 10 have cannabis use disorder (CUD), and about one-half those with CUD have moderate or severe disease with negative social, employment, or other adverse outcomes. Regular use of high THC-content products by adolescents and young adults is associated with several concerning risks, including an increased risk of psychosis (estimates range from about 2-fold to 11-fold increased risk), a higher risk of CUD, and self-harm in those with mood disorders. Cannabis use should be avoided in individuals at elevated risk of harms, including adolescents and young adults, those with bipolar or psychotic disorders, pregnant individuals, and those at risk for substance use disorders. The current evidence base is not sufficient to support the use of cannabis for the treatment of mental health conditions and demonstrates substantial risks of adverse effects. Clinicians should engage patients with mental health conditions in discussions about cannabis use because use is common, has an influence on mental health symptoms, and is likely an important modifiable risk factor for mental health conditions in some populations.
Comparable studies
Other narrative reviews on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Causal association between cannabis and psychosis: examination of the evidence | 2004 | Review | |
| Cannabis sativa: A comprehensive ethnopharmacological review of a medicinal plant with a long history. General (historical and pharmacological review) | 2018 | Review | |
| Psychiatric effects of cannabis | 2001 | Review | |
| Beyond THC: The New Generation of Cannabinoid Designer Drugs | 2011 | Review | |
| Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug | 2006 | Review |
Citations in the library
Cites 27
- Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study BMJ March 1, 2011
- Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases The British Journal of Psychiatry November 30, 2005
- The short-term impact of 3 smoked cannabis preparations versus placebo on PTSD symptoms: A randomized cross-over clinical trial PLoS One March 17, 2021
- Risk-thresholds for the association between frequency of cannabis use and the development of psychosis: a systematic review and meta-analysis Psychological Medicine March 24, 2022
- High-Concentration Delta-9-Tetrahydrocannabinol Cannabis Products and Mental Health Outcomes : A Systematic Review. Annals of Internal Medicine October 1, 2025
and 22 more in the library