Cannabis Use Linked to Doubled Risk of Psychosis
Adolescents who use cannabis face a significantly higher risk of developing serious psychiatric conditions—including psychotic and bipolar disorders—by young adulthood. According to a major new study published in JAMA Health Forum, teen cannabis use is associated with a doubling of the risk for these specific mental health diagnoses.
Tracking Nearly Half a Million Teens
Researchers from Kaiser Permanente, the Public Health Institute’s Getting it Right from the Start program, the University of California, San Francisco, and the University of Southern California tracked 463,396 adolescents aged 13 to 17 through age 26. The study, funded by the National Institute on Drug Abuse, utilized electronic health record data collected during routine pediatric screenings between 2016 and 2023.
The analysis revealed that cannabis use often preceded a psychiatric diagnosis by an average of 1.7 to 2.3 years. Even after researchers adjusted for pre-existing mental health conditions and other substance use, the association between cannabis consumption and the development of psychotic and bipolar disorders remained significant.
The Danger of Modern THC Potency
Lynn Silver, M.D., program director of the Getting it Right from the Start, a program of the Public Health Institute, and a study co-author, says the increasing potency of modern cannabis products creates an urgent public health concern.
Current data from California indicates that cannabis flower often exceeds 20% THC, while some concentrates contain levels surpassing 95%. Kelly Young-Wolff, Ph.D., lead author of the study and senior research scientist at the Kaiser Permanente Division of Research, emphasizes that these findings underscore the potential for long-term health consequences when cannabis is used during the teenage years.
Prevalence Among U.S. Youth
Cannabis remains the most commonly used illicit drug among U.S. adolescents. Data from the Monitoring the Future study shows that usage rates climb steadily as students age, rising from approximately 8% among eighth graders to 26% among twelfth graders. Furthermore, the 2024 National Survey on Drug Use and Health reported that more than 10% of teenagers aged 12 to 17 used cannabis within the previous year.
Socioeconomic Barriers and Health Disparities
The study also highlighted significant disparities in usage patterns. Researchers observed that cannabis use was more common among adolescents enrolled in Medicaid and those residing in neighborhoods with greater socioeconomic disadvantages. The authors noted that these findings raise concerns that the ongoing commercialization of cannabis could exacerbate existing inequalities in mental health outcomes across different populations.
Summary of Findings
- Doubled Risk: Adolescents who use cannabis face approximately twice the risk of developing psychotic and bipolar disorders.
- Temporal Link: In the study, cannabis use typically preceded psychiatric diagnoses by 1.7 to 2.3 years.
- Broad Scope: The research identified these risks even among adolescents who reported any cannabis use within the past year, suggesting that use during the teenage years may carry significant health implications.
- Public Health Concern: Experts are calling for an urgent public health response that reduces product potency, prioritizes prevention, limits youth exposure and marketing and treats adolescent cannabis use as a serious health issue.
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