Marijuana/Cannabis Research

Where We Stand

NAMI believes that public policies should be guided by credible, evidence-based research. NAMI supports public policies and laws that facilitate research into the risks and benefits that marijuana and other cannabis products have on people with mental health conditions.

Why We Care

People with mental illness report using marijuana at a rate of at least twice that of people without mental illness. Specifically, according to the 2019 National Survey on Drug Use and Health, 32.5% of adults with any mental illness and 39.8% of adults with serious mental illness use marijuana, compared to 14.2% of adults with no mental illness. While still evolving, research on the effects of marijuana and other cannabis products is insufficient, particularly as it relates to people with or at risk of developing mental illness.

A number of studies have documented a correlation between marijuana and the onset of schizophrenia or other psychotic conditions. Heavy use of marijuana and related products during teen and young adult years can particularly increase the risk of triggering the onset of schizophrenia and psychosis. While studies are limited and vary in their conclusions, there is some evidence that regular marijuana use may hasten the onset of symptoms of mood disorders (bipolar disorder and major depression) and anxiety disorders, particularly among young people. The Food and Drug Administration (FDA) recently issued a report that emphasized the lack of comprehensive research on the therapeutic effects of Cannabidiol (CBD), a compound found in marijuana, and expressed concerns about potential safety risks, including liver injuries, negative interactions with other drugs, drowsiness that may affect driving, and the possibility of male reproductive toxicity. However, preliminary studies suggest that CBD may have potential positive effects for some mental health symptoms. Additionally, the National Academies of Sciences, Engineering and Medicine reports that there is substantial evidence that cannabis is an effective treatment for chronic pain in adults.

Unfortunately, federal law and policy create barriers to researching the risks and benefits of the use of marijuana and other cannabis products. Since 1970, marijuana has been classified as a Schedule I Drug on the Schedule of Controlled Substances, which applies to drugs with a “high potential for abuse” and with “no currently accepted medical use.” U.S. researchers face regulatory hurdles to studying any Schedule I drugs when they attempt to research marijuana. This situation has limited the development of robust scientific research. As more states legalize the use of marijuana and other cannabis products, it is essential that credible, evidence-based research is available to fully understand the risks and potential benefits these products have on people with mental health conditions.

How We Talk About It

• Many people with mental health conditions report using marijuana or cannabis products to manage the symptoms of their mental health condition.
• Marijuana use is significantly higher among adults with mental illness compared to their peers without mental health conditions.
• However, we lack sufficient research to fully understand the impact of using marijuana and cannabis on the brain.
• While conclusions vary, some studies have found that marijuana use may trigger the appearance of schizophrenia symptoms or psychosis in young adults, and that regular use may accelerate the appearance of symptoms of mood or anxiety disorders.
• Meanwhile, some preliminary studies have shown that CBD (a compound found in cannabis) may reduce some mental health symptoms.
• We believe the federal government should support and accelerate research that helps us understand the impact of marijuana and other cannabis products — both in treating mental health conditions and its impact on the onset or relief of symptoms.