Source: 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.Investigators from multiple institutions conducted a retrospective study evaluating the association between cannabis use and an incident diagnosis of psychotic, bipolar, depressive, and anxiety disorders. Study participants were patients 13 to 17 years old who received health care at Kaiser Permanente Northern California facilities and completed at least 1 self-administered health screening questionnaire in conjunction with a well child care visit. In the questionnaire, adolescents were asked if they used marijuana during the previous year. They also were asked about use of alcohol and other substance use. Diagnoses of psychotic, bipolar, depressive, and anxiety disorders were identified using ICD codes. Participants were followed up until age 25. The association between cannabis use and an incident diagnosis of each of the psychiatric disorders was evaluated in separate Cox proportional hazard regression models, with multiple confounders included in the models. If an adolescent had a diagnosis of 1 of the psychiatric disorders of interest prior to the first time they completed the health screening questionnaire, they were excluded from the analysis of the association between cannabis use and that disorder. Secondary analyses that included a previous diagnosis of other psychiatric disorders also were conducted.Data were analyzed on 463,396 adolescents who completed at least 1 health screening questionnaire; 46% of participants completed the questionnaire ≥2 times. Mean duration of follow-up was approximately 3.5 years. At the time they completed their first health screening questionnaire, 26,345 (5.7%) study participants reported cannabis use, 31,445 (6.8%) alcohol use, and 9,872 (2.1%) other substance use. Overall, an incident diagnosis of psychotic disorder was made in 4,105 adolescents (0.24 per 1,000 person years), 4,061 (0.24 per 1,000 person years) were diagnosed with a bipolar disorder, 62,137 (4.5 per 1,000 person years) with a depressive disorder, and 73,096 (5.64 per 1,000 person years) with an anxiety disorder. Cannabis use was associated with an increased risk of incident psychotic disorder (adjusted hazard ratio aHR, 2.19; 95% confidence interval CI, 1.97, 2.42), bipolar disorder (aHR, 2.01; 95% CI, 1.82, 2.22), depressive disorder (aHR, 1.34; 95% CI, 1.30, 1.39), and anxiety disorder (aHR, 1.24; 95% CI, 1.21, 1.28). For depressive and anxiety disorders, the association with cannabis use decreased with age; for both disorders there was no significant increase in risk associated with prior cannabis use when participants were 21–25 years old. In the secondary analyses, after adjusting for other psychiatric disorders, the association between cannabis use and each of the psychiatric disorders of interest was attenuated but remained statistically significant with each disorder.The authors conclude that cannabis use in adolescents was associated with an increased risk of incident diagnoses of psychotic, bipolar, depressive, and anxiety disorders.Dr Raphael has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.Cannabis remains one of the most widely used psychoactive substances in the United States.1 The current study adds to the growing body of evidence that cannabis use can cause significant psychiatric harm. Another recent study of more than 24,000 pediatric patients with cannabis use disorder found higher risks of schizophrenia, depression, and anxiety compared with youths who had other substance use disorders.2 Biological plausibility has been demonstrated in preclinical studies. Early cannabis exposure is thought to cause disruption of adolescent brain development.3 In a longitudinal cohort of 799 cannabis-naïve adolescents, cannabis use between the ages of 14–19 was associated with measurable alterations cerebral cortical development on MRI. (See AAP Grand Rounds. 2021;464:40.)4The current study has multiple strengths. The sample size was very large and diverse. Screening for both cannabis use and mental health disorders was universal. Sensitivity analyses showed that the associations remained even after excluding participants with other psychiatric disorders and when outcomes were defined using both narrow and broad ICD codes. While the current researchers did not examine the effect of extent of use or strength of cannabis formulations, previous studies indicate that higher potency formulations (>10%), and frequent use are associated with higher risk of adverse mental health outcomes.5Despite well-documented health risks associated with cannabis use,1 adolescents increasingly perceive cannabis as less harmful. This decline in perceived risk has been particularly pronounced since cannabis legalization.6 On an individual level, addressing this misconception and harm reduction through delaying use and minimizing the use of high potency cannabis products is important. However, individual counseling alone is insufficient. System-level policy interventions may play a critical role in mitigating adolescent harm. Evidence-informed strategies include decriminalization while maintaining opposition to recreational legalization, dispensary zoning, age verification, mandatory product testing and potency labeling, and funding for sustainable youth=focused prevention programs.7Cannabis use, particularly in early adolescence, is associated with increased risk of psychiatric disorders.
A Mon, study studied this question.