Most Cannabis Use Came From People With Recent Mental Illness in a Large U.S. Survey | Research

The takeaway

Adults with a past-year mental illness were far more likely to use cannabis and to meet criteria for a cannabis use disorder, and they accounted for most of the cannabis consumed in the sample.

Readers working in mental health, addiction, epidemiology, or policy who want population-level context on where cannabis use and cannabis use disorders concentrate.

83%
estimated share of all cannabis consumed by people with a past-year mental illness in this nationally representative sample

What the researchers found

People reporting a 12-month mental illness had much higher rates of cannabis involvement than those without. Weekly use was 4.4% versus 0.6%, less-than-weekly use was 5.4% versus 1.1%, and cannabis use disorders were 4.0% versus 0.4%. After adjusting for demographics and other substance use disorders, the odds of any cannabis use were 2.5 times higher and the odds of a cannabis use disorder were 3.2 times higher among people with a past-year mental illness.

Use and disorder were not evenly distributed across diagnoses. Associations were strongest for bipolar disorder, other substance use disorders, and certain personality disorders, including antisocial, dependent, and histrionic personality disorder.

Although only a subset of adults reported mental illness in the past year, they represented 72% of all cannabis users in the survey and were estimated to account for 83% of the cannabis consumed, based on self-reported frequency and typical daily dose.

Why it matters

Public health debates often treat cannabis use as broadly distributed across the population. This analysis suggests that, at least in 2001 to 2002, use and cannabis use disorders clustered among people with recent mental illness, with implications for how researchers characterize risk and where services are typically directed.

The numbers in context

- Sample: 43,070 U.S. adults, 2001 to 2002 nationally representative survey

- Weekly cannabis use: 4.4% with past-year mental illness vs 0.6% without (P<0.0001)

- Less-than-weekly use: 5.4% vs 1.1% (P<0.0001)

- Cannabis use disorder: 4.0% vs 0.4% (P<0.0001)

How the study worked

Researchers analyzed 43,070 U.S. adults from the 2001 to 2002 National Epidemiologic Survey on Alcohol and Related Conditions, a nationally representative household survey. Psychiatric diagnoses were assessed with the Alcohol Use Disorders and Associated Disabilities Interview Schedule-IV, covering DSM-IV Axis I and II conditions over the past 12 months. Outcomes included cannabis use frequency (at least weekly, or less than weekly) and DSM-IV cannabis use disorders. Logistic models adjusted for sociodemographic factors and other substance use disorders. The team also estimated the share of total cannabis consumption attributable to people with and without mental illness using self-reported frequency and daily dose.

Who was studied

N=43,070 adults aged 18 and above, National Epidemiologic Survey on Alcohol and Related Conditions, Country not specified.

What this study cannot tell us

Cross-sectional design cannot establish which came first, mental illness or cannabis involvement. Diagnoses relied on a structured interview (AUDADIS-IV), which can misclassify some Axis I and II conditions. Cannabis measures came from self-reported frequency and typical daily dose, with no verification of product potency, THC-to-CBD ratios, or mode of use. The consumption estimate (83%) depends on self-report–based calculations rather than direct measurement. Data were collected in 2001 to 2002, before major shifts in legalization, product potency, and market dynamics, which may limit relevance to current patterns. Residual confounding is possible despite adjustment for demographics and other substance use disorders.

How to read the evidence

Rated moderate: very large, nationally representative survey with adjusted models and diagnosis via a standardized interview, but cross-sectional, reliant on self-report, and based on older data collected in 2001 to 2002.

When this study was published

Published in 2013 using 2001 to 2002 data. This predates widespread legalization, rising product potency, and today’s retail market, which may shift both prevalence and who is most affected.

The bigger picture

The concentration of cannabis use and cannabis use disorders within psychiatric populations challenges the idea that cannabis exposure is evenly spread across adults. The pattern aligns with several possible explanations, including shared vulnerability factors, self-medication, or environmental stressors that travel with both mental illness and substance use. The study reports strong associations, not causes, and it highlights diagnostic groups where cannabis involvement was most common in this dataset, such as bipolar disorder and certain personality disorders.

Replication

Not stated in abstract.

Funding

Not reported in abstract.

Conflicts of interest

Not reported in abstract.

Questions still open

Do these associations persist in more recent cohorts with higher-potency products and wider legal access?
How much of the link reflects shared risk factors versus self-medication versus social and environmental variables?
Within specific diagnoses like bipolar disorder or antisocial personality disorder, what features track most strongly with cannabis use disorder risk?
How do co-occurring alcohol and tobacco use shape these patterns?
Would clinician-rated illness severity or treatment engagement change the observed associations?

Common questions

Does this mean cannabis causes mental illness?

No. The study is cross-sectional. It found that cannabis use and cannabis use disorders were more common among people with recent mental illness, but it cannot determine direction or cause.

Which diagnoses were most associated with cannabis use and disorder?

Bipolar disorder, other substance use disorders, and certain personality disorders, including antisocial, dependent, and histrionic personality disorder, showed the strongest associations in this analysis.

How much of the cannabis consumed came from people with mental illness?

Using self-reported frequency and daily dose, the authors estimated that 83% of cannabis consumed in the sample came from people with a past-year mental illness.

Read the original research

Cannabis use and cannabis use disorders among individuals with mental illness

Comprehensive Psychiatry, 54(6), 589-598

Comprehensive Psychiatry is a peer-reviewed medical journal covering psychiatry.

View on PubMed ↗

Citation

Lev-Ran, Shaul; Le Foll, Bernard; McKenzie, Kwame; George, Tony P.; Rehm, Jurgen. (2013). Cannabis use and cannabis use disorders among individuals with mental illness. Comprehensive Psychiatry, 54(6), 589-598.