Research study · American Journal of Psychiatry · 2026
Association of Cannabis Use Disorder Versus Other Substance Use Disorders With Psychiatric Conditions: A Propensity-Matched Retrospective Cohort Analysis
Verified on PubMed Oxford CEBM Level 2B: Clinical Cohort Study
A 2026 cohort study in American Journal of Psychiatry tested cannabis in marijuana abuse. The results were mixed and depended on age. This study shows that the mental health picture for cannabis problems is not the same for everyone: it looks different for adults than for young people, and it is not simply the same.
In plain language
Study overview
Researchers looked at health records of people diagnosed with a problem related to using cannabis, and compared their mental health to people diagnosed with problems related to other drugs. They grouped the results by adults and by young people.
Findings
The results were mixed and depended on age. Adults with a cannabis problem had fewer serious mental health diagnoses than adults with problems from other drugs, while young people with a cannabis problem had more of them.
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The deeper readScientific analysis
Source document is a MedicalResearch.com blog interview with lead author Ryan C. Nicholson, MD MPH, summarizing the study. Full abstract not provided in the supplied text. The blog reports a propensity-matched retrospective cohort analysis comparing psychiatric outcomes in patients with cannabis use disorder versus other substance use disorders, using TriNetX electronic health record data.
The paper
Citation
Nicholson RC, Choi UE, Mojtabai R, Thrul J Association of Cannabis Use Disorder Versus Other Substance Use Disorders With Psychiatric Conditions: A Propensity-Matched Retrospective Cohort Analysis. American Journal of Psychiatry (2026). PubMed 41776722 · DOI
Read the abstract as published
OBJECTIVE: The authors compared the risk of mental disorders between patients with cannabis use disorder (CUD) and those with other substance use disorders (SUDs). METHODS: The TriNetX Research Network was queried to identify patients with SUDs and no preceding mental disorders and compare 1) adult patients with CUD only versus those with other SUDs, 2) pediatric patients with CUD only versus those with other SUDs, and 3) adult patients with CUD plus another SUD versus those with comorbid noncannabis SUDs. Propensity score matching was performed on demographic characteristics and 24 risk factors or comorbidities. Subsequent diagnosis of schizophrenia and other common mental disorders was assessed. RESULTS: Compared to adults with other SUDs, those with noncomorbid CUD (N=345,903 for both cohorts) had a lower risk of schizophrenia (0.34% vs. 0.42%; relative risk [RR]=0.81, 95% CI=0.75, 0.88), depression (1.35% vs. 1.74%; RR=0.78, 95% CI=0.75, 0.81), and psychotic disorders (0.36% vs. 0.52%; RR=0.68, 95% CI=0.63, 0.73). Compared to pediatric patients with other SUDs, those with CUD (N=24,793 for both cohorts) had a higher risk of schizophrenia (0.29% vs. 0.19%; RR=1.52, 95% CI=1.06, 2.19), depression (1.65% vs. 1.27%; RR=1.30, 95% CI=1.13, 1.51), and anxiety disorders (8.13% vs. 6.71%; RR=1.21, 95% CI=1.14, 1.29). Compared to adult patients with other SUDs, those with CUD and a comorbid SUD (N=203,916 for both cohorts) had a decreased risk of schizophrenia (1.94% vs. 2.25%; RR=0.86, 95% CI=0.83, 0.90), depression (3.98% vs. 5.67%; RR=0.70, 95% CI=0.68, 0.72), bipolar disorder (4.23% vs. 5.60%; RR=0.76, 95% CI=0.74, 0.78), and anxiety disorders (16.20% vs. 21.36%; RR=0.76, 95% CI=0.75, 0.77). CONCLUSIONS: CUD-associated mental health risks varied by age and comorbid SUDs, possibly due to earlier onset of mental disorders in cannabis users or age-related differences in CUD effects.
Abstract text as indexed by PubMed for this identifier.
Limitations the authors noted
Reliance on electronic health record data and diagnostic codes, which may miss cases. Dose, frequency and potency of cannabis use could not be assessed. Observational design precludes causal inference. Individuals not seeking care are underrepresented. Retrospective design with TriNetX network data.
In practice
Why this matters
This study shows that the mental health picture for cannabis problems is not the same for everyone: it looks different for adults than for young people, and it is not simply the same as problems with other drugs. It does not show that cannabis causes these conditions, and it cannot tell us how much or how strong the cannabis was. A reader should take away that young people deserve extra attention and that cannabis is not a safe choice, while the questions about dose and product type remain open.
Frequently asked questions
Clinical Questions & Answers
What were the primary clinical findings regarding Cannabis and Marijuana abuse?
The results were mixed and depended on age. Adults with a cannabis problem had fewer serious mental health diagnoses than adults with problems from other drugs, while young people with a cannabis problem had more of them.
What study limitations or clinical safeguards should patients keep in mind?
Reliance on electronic health record data and diagnostic codes, which may miss cases. Dose, frequency and potency of cannabis use could not be assessed. Observational design precludes causal inference.
Browse related research
Condition: Marijuana abuse Condition: Mental disorders Condition: Substance-related disorders Topic: Cannabis
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Reviewed by Dr. Caplan on October 26, 2026.
This page is general education about a published study. It is not medical advice and does not create a doctor-patient relationship. For care specific to you, book a consultation.