In a groundbreaking longitudinal investigation published in JAMA Health Forum, researchers reveal compelling evidence linking adolescent cannabis use with markedly increased risks of developing severe psychiatric disorders by young adulthood. The extensive study tracked the health trajectories of nearly half a million adolescents, ages 13 to 17, following them through to age 26. This comprehensive analysis, grounded in electronic health record data collected during routine pediatric visits from 2016 to 2023, underscores cannabis use as a potent and potentially modifiable risk factor for future mental health conditions, including psychotic, bipolar, depressive, and anxiety disorders.
The longitudinal design of this study sets it apart by providing temporal clarity—cannabis consumption consistently preceded the onset of psychiatric conditions by an average interval ranging from 1.7 to 2.3 years. This temporal association enhances the plausibility of a causal relationship, addressing long-standing questions about cannabis’s role in mental illness etiology. Utilizing a massive sample size of 463,396 adolescents across diverse demographic backgrounds, the study was powered to discern robust statistical associations while adjusting for confounders such as prior mental health status and other substance use.
Notably, the findings highlight a doubling in the risk of incident psychotic and bipolar disorders among adolescents reporting past-year cannabis use. Psychotic disorders, characterized by hallucinations, delusions, and impaired reality testing, along with bipolar disorder, involving profound mood dysregulation with episodes of mania and depression, represent some of the most debilitating psychiatric illnesses. The observed associations with depressive and anxiety disorders, while less pronounced, remain clinically significant, suggesting that cannabis use during critical neurodevelopmental windows disrupts multiple neural circuits linked to emotional regulation and cognitive processing.
Lead author Kelly Young-Wolff, Ph.D., from the Kaiser Permanente Division of Research, emphasized that the study measured any self-reported past-year cannabis consumption, rather than focusing solely on heavy use or cannabis use disorder. This inclusive approach provides vital insights relevant to widespread adolescent behavior patterns, given that cannabis remains the most commonly used illicit substance among U.S. teens. The findings therefore carry broad public health implications, as even moderate use could contribute to elevated psychiatric risk profiles.
The study’s timing coincides with dramatic shifts in cannabis potency and commercialization. Average THC concentrations in California cannabis flower have soared past 20%, with concentrated extracts exceeding 95% THC, exposing adolescents to unprecedented biochemical doses. This intensification of psychoactive exposure may amplify cannabis’s neurotoxic potential during adolescence—an especially vulnerable developmental stage marked by ongoing synaptic pruning, myelination, and maturation of frontolimbic brain regions implicated in executive control and emotional regulation.
Moreover, the research elucidates socioeconomic dimensions of cannabis use, revealing higher prevalence rates among Medicaid-enrolled youths and those residing in economically deprived neighborhoods. This intersection raises pressing concerns about exacerbating existing mental health disparities if cannabis commercialization expands unchecked, disproportionately burdening already vulnerable populations with heightened psychiatric morbidity.
Dr. Lynn Silver, M.D., program director of the Getting it Right from the Start initiative, underscored the urgent need for a robust public health response. The evidence mandates actions aimed at reducing product potency, curbing youth exposure through stringent marketing restrictions, prioritizing prevention efforts, and reframing adolescent cannabis use as a serious health concern rather than a benign social behavior. Such measures are crucial to mitigate the burgeoning mental health crisis linked to adolescent substance exposure.
The methodological rigor of this investigation lies in its utilization of electronic health records (EHRs) amassed during routine pediatric visits spanning seven years, enhancing generalizability and ecological validity. Through universal screening within clinical care frameworks, researchers captured self-reported cannabis use in a real-world setting, reducing selection bias intrinsic to voluntary surveys or clinical referrals. The integration of rich longitudinal EHR data enabled detailed temporal sequencing and adjustment for confounding variables, bolstering causal inference.
Funding from the NIH’s National Institute on Drug Abuse (NIDA) supported this multi-institutional collaboration involving Kaiser Permanente, the Public Health Institute, University of California San Francisco, and University of Southern California. This consortium approach harnessed diverse expertise in epidemiology, biostatistics, psychiatry, and public health policy, ensuring robust analytic frameworks and nuanced interpretation of findings.
This investigation complements prior epidemiological and neurobiological evidence linking adolescent cannabis exposure with adverse outcomes, yet distinguishes itself by encompassing a massive, diverse cohort followed prospectively over nearly a decade. The doubling of risk for psychosis and bipolar disorder—both associated with substantial disability and healthcare costs—spotlights cannabis’s contribution to the psychiatric disease burden and fuels urgency for preventive interventions spanning policy, healthcare, and education sectors.
Parents, educators, and healthcare providers must be equipped with accurate, trusted, evidence-based information to facilitate informed decision-making and early intervention. Given the normalization of cannabis in popular culture and increasing legal availability, counter-narratives emphasizing adolescent neurodevelopmental vulnerability and long-term mental health risks are essential.
In conclusion, this landmark study provides compelling longitudinal evidence that adolescent cannabis use is a significant risk factor for serious psychiatric disorders by young adulthood. The findings demand urgent public health strategies to reduce adolescent cannabis exposure and mitigate deepening health disparities fueled by socioeconomic inequities. As cannabis potency intensifies and marketing proliferates, the imperative to protect developing minds through prevention, education, and policy reform becomes ever more critical.
Subject of Research: People
Article Title: Adolescent Cannabis Use and Risk of Psychotic, Bipolar, Depressive, and Anxiety Disorders
News Publication Date: 20-Feb-2026
Web References: JAMA Health Forum DOI
Keywords: adolescent cannabis use, psychotic disorders, bipolar disorder, depressive disorders, anxiety disorders, mental health risk, longitudinal study, electronic health records, THC potency, public health policy, socioeconomic disparities, neurodevelopment
Tags: adolescent cannabis use and mental healthadolescent substance use and mental illnessbipolar disorder risk from cannabiscannabis use and psychiatric disorderscannabis use and psychotic disorders riskcausal relationship between cannabis and psychosisearly cannabis exposure and bipolar disorderelectronic health records in mental health researchlarge-scale adolescent health studylongitudinal study on cannabis effectsmental health outcomes of teen cannabis usemodifiable risk factors for psychiatric disorders
