Adolescent cannabis use tied to greater psychiatric disorder risk

The risks of developing psychiatric disorders are significantly increased among adolescents using cannabis, according to a recent study published in JAMA Health Forum.¹

In adolescents aged 13 to 17 years, cannabis use was linked to a 2-fold increase in the risks of both incident psychotic and bipolar disorders. Significant increases in depression and anxiety disorder risks were also observed, highlighting adolescent cannabis exposure as risk factor of mental illness development.¹

“As cannabis becomes more potent and aggressively marketed, this study indicates that adolescent cannabis use is associated with double the risk of incident psychotic and bipolar disorders, two of the most serious mental health conditions,” said Lynn Silver, MD, study co-author and program director of the Getting it Right from the Start program.¹

Psychiatric assessment

The retrospective cohort study was conducted to evaluate psychiatric disorder development following cannabis use.² Data was obtained from Kaiser Permanente Northern California (KPNC), a health care delivery system with more than 4.6 million members.

Adolescents aged 13 to 17 years in the KPNC completed the Teen Well-Check Questionnaire (TWCQ) between January 1, 2016, and December 31, 2023. KPNC enrollment at well-child visit and responding to a question about past-year cannabis use were required for inclusion.²

Exclusion criteria included having an outcome diagnosis before or during the index date. Psychiatric disorders were identified based on International Classification of Diseases, Ninth Revision and Tenth Revision outcomes.²

Reporting cannabis use and participant characteristics

The TWCQ was only completed at each well-child visit, with responses to the question about past-year cannabis use including yes and no. Categories of following incident psychiatric disorders included psychotic, bipolar, depressive, and anxiety.²

Well-child visit, sex, race and ethnicity, US Census-based neighborhood deprivation index (NDI), and insurance type were reported as covariates. Alongside cannabis use, the TWCQ assessed alcohol and other substance use.²

There were 463,396 adolescents included in the analysis, 50.5% of whom were male, 49.4% female, and less than 0.1% other or unknown sex. The mean age among these patients was 14.5 at baseline, and 29.5% were Hispanic, 20.2% Asian, 7.6% Black, 33% White, and 4.1% multiracial or other races and ethnicities.²

An older age, female sex, and race of Hispanic, non-Hispanic Black, and non-Hispanic White were more likely to be reported in adolescents using cannabis. These patients also more often had a greater NDI, Medicaid, and alcohol and substance use.²

Increased incidence of psychiatric disorders

There were 4105 diagnoses of incident psychotic disorder reported across a mean 3.7 years of follow, vs 4061 diagnoses of bipolar disorder across a mean 3.7 years, 62,137 of depressive disorder across a mean 3.3 years, and 73,096 of anxiety disorder across a mean 3.3 years. These disorders were more likely in adolescents with cannabis use, with the following adjusted hazard ratios (AHRs):²

• 2.19 for psychotic disorders
• 2.01 for bipolar disorder
• 1.34 for depressive disorder
• 1.24 for anxiety disorder

Investigators noted declining AHRs as age increased. AHRs for depressive disorder were 1.78 at ages 13 to 15 years, 1.35 at ages 16 to 17 years, 1.21 at ages 18 to 20 years, and 0.87 at ages 21 to 25 years, with the latter being nonsignificant. For anxiety disorder, these AHRs were 1.47, 1.24, 1.24, and nonsignificant at 0.95.²

These results indicated links for adolescent cannabis use with incident psychotic, bipolar, depressive, and anxiety disorders. Investigators concluded this data could be used to inform policies that limit youth access to cannabis.²

“The evidence increasingly points to the need for an urgent public health response — one that reduces product potency, prioritizes prevention, limits youth exposure and marketing and treats adolescent cannabis use as a serious health issue, not a benign behavior,” said Silver.¹

References

1. Study: Adolescent cannabis use linked to doubling risk of psychotic and bipolar disorders. Public Health Institute. February 20, 2026. Accessed February 24, 2026. https://www.eurekalert.org/news-releases/1117004?
2. Young-Wolff KC, Cortez CA, Alexeeff SE, et al. Adolescent cannabis use and risk of psychotic, bipolar, depressive, and anxiety disorders. JAMA Health Forum. 2026;7(2):e256839. doi:10.1001/jamahealthforum.2025.6839