Cannabis & Mental Health Research

NIH NIDA-Funded | Columbia University | Evidence-Based

Translating large-scale epidemiological research into actionable knowledge for clinicians, policymakers, parents, and patients

Dr. Ryan Sultan is an NIH NIDA-funded researcher and Assistant Professor of Clinical Psychiatry at Columbia University Irving Medical Center. His cannabis research program investigates the psychiatric consequences of adolescent cannabis use through large-scale epidemiological studies, with a focus on informing clinical practice and public health policy during a period of rapid cannabis legalization.

Related Pages

Is Cannabis Addictive? | Cannabis Withdrawal | ADHD & Substance Use | All Publications | Research Grants | Research Overview

Additional Data Points

Sultan RS, et al. "Adolescent Cannabis Use and Risk of Psychotic, Mood, and Anxiety Disorders."

JAMA Health Forum. 2026.

N=463,396 adolescents. Cannabis use associated with AHR 2.19 for psychotic disorders, 2.01 for bipolar disorder, 1.34 for depressive disorder. Kaiser Permanente Northern California EHR data, 2016-2023.

Sultan RS, et al. "Cannabis Use and Behavioral, Emotional, and Academic Outcomes Among US Adolescents."

Pediatrics. 2026.

26% of teens report cannabis use. Cannabis use linked to worse grades, greater emotional distress, and increased behavioral problems. Nationally representative NSDUH data.

Sultan RS, Olfson M, Engel C, Crystal S. "Nondisordered Cannabis Use Among US Adolescents."

JAMA Network Open. 2023;6(5):e2314422.

N=70,000+ adolescents (NSDUH 2015-2019). Even nondisordered cannabis use associated with 2x depression risk, 2.6x suicidal ideation, 4x arrest rates. Established that cannabis carries psychiatric risk across the full use spectrum — not just among those with use disorders.

Sultan RS, Olfson M, Engel C, Crystal S. "Early Cannabis Exposure and Subsequent Risk of Psychiatric Disorders Among US Adolescents."

JAMA Network Open / Related analyses.

Earlier age of first cannabis use associated with greater psychiatric morbidity. Supports AAP and AACAP recommendations to delay cannabis exposure and strengthen prevention during early adolescence.

American Academy of Pediatrics (AAP)

The AAP has issued its strongest-ever position on cannabis and youth:

• Opposes legalization of marijuana for individuals under age 21
• Opposes "medical marijuana" outside of FDA regulatory process for patients under 21
• Recommends all pediatricians screen for cannabis use at well-child visits
• Supports decriminalization of marijuana for minors to reduce collateral consequences
• Warns that cannabis products should be regulated, taxed, and kept away from youth
• Calls for research on cannabis health effects, particularly during brain development

Source: AAP Committee on Substance Use and Prevention. "The Impact of Marijuana Policies on Youth." Pediatrics. 2023;151(1):e2022060645.

American Academy of Child and Adolescent Psychiatry (AACAP)

The AACAP has published formal policy statements and clinical guidelines on cannabis:

• Opposes cannabis use by adolescents and young adults under 21
• Recommends universal screening of all adolescent patients for cannabis use
• Identifies cannabis as a significant risk factor for psychosis, depression, and anxiety in youth
• Supports evidence-based prevention programs in schools and communities
• Warns that increasing THC potency amplifies psychiatric risk for young users
• Calls for regulation of advertising and product packaging to protect youth

Source: AACAP Marijuana Policy Statement. Updated 2023. aacap.org

American Psychiatric Association (APA)

The APA has adopted formal positions on cannabis that emphasize risk and the need for caution:

• Opposes recreational use of cannabis, citing mental health risks
• Expresses concern about insufficient regulation of THC content in legal products
• Notes the lack of FDA approval for most cannabis products marketed for health purposes
• Supports further research on cannabis effects, including controlled clinical trials
• Recognizes Cannabis Use Disorder in the DSM-5 as a diagnosable psychiatric condition
• Calls for public education on the mental health risks of cannabis, particularly for young people

Source: APA Position Statement on Marijuana. American Psychiatric Association. psychiatry.org

World Health Organization (WHO)

The WHO has conducted extensive reviews of cannabis health effects:

• Confirmed that cannabis use is associated with increased risk of psychotic disorders
• Identified cannabis as a drug of dependence, with approximately 1 in 10 users developing dependence (higher for adolescent-onset users)
• Warned about the impact of cannabis on adolescent brain development and cognitive function
• Recommended member states implement prevention programs targeting youth

Source: WHO Expert Committee on Drug Dependence, 2019. Technical Report Series.

U.S. Surgeon General

The U.S. Surgeon General has issued an advisory on marijuana use and the developing brain:

• Warns that marijuana poses risks to the developing brain through age 25
• Notes that marijuana use during pregnancy can affect fetal brain development
• States that no amount of marijuana use during pregnancy or adolescence is known to be safe
• Calls for a public health approach to cannabis that prioritizes youth protection

Source: U.S. Surgeon General's Advisory: Marijuana Use and the Developing Brain. 2019.

Does cannabis cause mental health problems?

Yes. Large-scale research consistently shows cannabis use increases the risk of multiple psychiatric disorders. A study of over 70,000 adolescents published in JAMA Network Open (2023) found cannabis use associated with a 2-4x increased risk of psychiatric disorders including depression, anxiety, and psychosis. A 2026 study of 463,396 adolescents in JAMA Health Forum confirmed cannabis more than doubles psychosis risk (AHR 2.19). The risk is especially pronounced for adolescents, daily users, and those using high-potency THC products.

Sources: Sultan et al., JAMA Network Open, 2023; Sultan et al., JAMA Health Forum, 2026; Gobbi et al., JAMA Psychiatry, 2019

Can marijuana cause psychosis?

Yes. Cannabis use significantly increases the risk of psychotic disorders. The Kaiser Permanente study of 463,396 adolescents found cannabis use more than doubles the risk (adjusted hazard ratio 2.19). Daily high-potency use increases risk approximately 4-fold (Di Forti et al., Lancet Psychiatry, 2019). Critically, approximately 50% of individuals who experience cannabis-induced psychosis go on to develop a permanent psychotic disorder such as schizophrenia (Starzer et al., Am J Psychiatry, 2018).

Sources: Sultan et al., JAMA Health Forum, 2026; Di Forti et al., Lancet Psychiatry, 2019; Starzer et al., Am J Psychiatry, 2018

Is marijuana addictive?

Yes. Cannabis Use Disorder (CUD) affects approximately 22-30% of cannabis users. The DSM-5 recognizes CUD as a diagnosable condition with mild, moderate, and severe categories. Risk factors include early onset of use, daily use, and use of high-potency products. Withdrawal symptoms include irritability, sleep difficulty, decreased appetite, cravings, and anxiety. In 2022, an estimated 6.3 million Americans met diagnostic criteria for CUD (NSDUH). Among adolescents who use cannabis, approximately 1 in 6 develop dependence.

Sources: Hasin et al., JAMA Psychiatry, 2015; NSDUH, 2022; Winters & Lee, 2008

How does cannabis affect the teenage brain?

The adolescent brain is particularly vulnerable to cannabis because the endocannabinoid system plays a critical role in brain development, which continues until approximately age 25. Cannabis use during adolescence has been associated with: reduced white matter integrity, impaired working memory and attention, lower IQ (up to 8-point decline with heavy use per Meier et al., PNAS, 2012), increased risk of psychiatric disorders (2-4x), and disrupted prefrontal cortex development affecting decision-making and impulse control. The ABCD Study, following 11,000+ children, is documenting these effects in real time.

Sources: Meier et al., PNAS, 2012; Gruber et al., Annals of the NYAS, 2021; ABCD Study; U.S. Surgeon General Advisory, 2019

How potent is marijuana today compared to the past?

THC potency has increased approximately 4-fold over the past three decades. Average THC content rose from 3.96% in 1995 to 16.14% in 2022 (University of Mississippi Potency Monitoring Program). Concentrates and extracts can contain 60-90% THC. Edibles can deliver unpredictable doses, contributing to the 1,375% increase in pediatric poisoning (2017-2021). This dramatic increase in potency means today's cannabis products carry substantially greater risk than those studied in earlier research.

Sources: ElSohly et al., Biological Psychiatry, 2016 (updated 2023); Potency Monitoring Program, University of Mississippi; Whitehill et al., Pediatrics, 2023

Does cannabis help with anxiety or depression?

While some users report short-term anxiety relief, longitudinal research shows cannabis worsens anxiety and depression over time. A meta-analysis of 69 studies found cannabis use associated with increased odds of developing both anxiety disorders (OR 1.25) and depression (OR 1.37) (Gobbi et al., JAMA Psychiatry, 2019). Even nondisordered cannabis use doubles depression risk in adolescents (Sultan et al., JAMA Network Open, 2023). CBD alone shows some promise for anxiety in preliminary research, but THC-containing products generally worsen mental health outcomes long-term.

Sources: Gobbi et al., JAMA Psychiatry, 2019; Sultan et al., JAMA Network Open, 2023; Lowe et al., Lancet Psychiatry, 2019

How many teens use cannabis?

According to the 2025 Monitoring the Future survey, 25.7% of 12th graders reported past-year cannabis use. Additionally, 19.8% of 10th graders and 11.4% of 8th graders reported past-year use. Among teen cannabis users, 71% now use vape devices to consume cannabis, which delivers higher THC concentrations and is harder for parents to detect. Perceived risk continues to decline: only 20.6% of 12th graders view regular cannabis use as carrying "great risk" — a historic low.

Sources: Monitoring the Future 2025 (University of Michigan / NIDA); Patrick et al., 2024; NSDUH, 2022

What do professional medical organizations say about cannabis?

Major medical organizations are united in opposing recreational cannabis use, particularly for youth. The American Academy of Pediatrics (AAP) opposes legalization for individuals under 21 and warns against adolescent use. The American Academy of Child and Adolescent Psychiatry (AACAP) recommends screening all adolescents for cannabis use. The American Psychiatric Association (APA) opposes recreational cannabis use and has expressed concern about insufficient regulation. The U.S. Surgeon General has issued a formal advisory warning that marijuana poses risks to the developing brain through age 25. See the Professional Positions section above for detailed summaries.

Sources: AAP Policy Statement, Pediatrics, 2023; AACAP Policy Statement, 2023; APA Position Statement; U.S. Surgeon General Advisory, 2019