Men are twice as likely to have cannabis use disorder, but mental illness narrows the gender gap | Research

The takeaway

A systematic review of 37 studies found men are twice as likely as women to have CUD overall, but among people with certain mental illnesses, the sex gap narrows or reverses.

Addiction clinicians, mental health researchers, and policymakers designing sex-specific prevention programs.

Males 2x more likely to have CUD overall, but pattern reverses for anxiety disorders

What the researchers found

In the CUD-only group, males were twice as likely as females to have CUD (OR=2.0). Among mental illnesses, males were more likely to have CUD with schizophrenia (OR~2.6) and other psychotic, mood, and substance use disorders. However, a reversed pattern (females more likely) was observed for anxiety disorders and antisocial personality disorder (OR=0.8). Mental illness increased the likelihood of CUD among females for most conditions except psychotic disorders and depression.

Why it matters

Understanding sex differences in CUD across mental illness diagnoses is critical for tailoring prevention and treatment. The finding that mental illness differentially affects CUD risk by sex suggests that screening and intervention strategies should be diagnosis-specific.

The numbers in context

37 studies. CUD-only: males 2x more likely (OR=2.0, CI=1.9-2.1). CUD+schizophrenia: males ~2.6x more likely. CUD+anxiety/ASPD: females slightly more likely (OR=0.8, CI=0.7-1.0). Mental illness increased female CUD likelihood except for psychotic disorders and depression.

How the study worked

Systematic review and meta-analysis of 37 studies including clinical trials, cohort, and case-control studies. Generated pooled odds ratios comparing sex differences in CUD prevalence among individuals with and without mental illnesses. Meta-analysis was inconclusive due to high heterogeneity.

What this study cannot tell us

High heterogeneity prevented valid meta-analysis across MI groups. Different studies used different CUD definitions. Cannot determine directionality (whether MI leads to CUD or vice versa). Publication bias possible.

How to read the evidence

Large systematic review of 37 studies. Meta-analysis was inconclusive due to heterogeneity, but qualitative findings are consistent.

When this study was published

2021 systematic review and meta-analysis.

The bigger picture

The standard narrative that CUD is primarily a male problem is oversimplified. When mental illness enters the picture, the sex distribution shifts substantially for certain diagnoses, meaning clinicians treating women with anxiety disorders or antisocial personality should be particularly vigilant for CUD.

Questions still open

Why does anxiety disorder reverse the sex ratio for CUD? Do biological or social factors drive the sex-specific patterns? Would sex-specific CUD treatments improve outcomes?

Common questions

Are men or women more likely to have cannabis use disorder?

Overall, men are twice as likely to have CUD. However, among people with anxiety disorders or antisocial personality disorder, women were slightly more likely to have CUD.

How does mental illness affect the sex gap in CUD?

Mental illness generally increased the likelihood of CUD among women (narrowing the sex gap), except for psychotic disorders and depression where the male predominance persisted.

Read the original research

A systematic review and meta-analysis of sex differences in cannabis use disorder amongst people with comorbid mental illness.

The American journal of drug and alcohol abuse, 47(5), 535-547

View on PubMed ↗Publisher’s paper ↗

Citation

Kozak, Karolina; H Smith, Philip; Lowe, Darby J E; Weinberger, Andrea H; Cooper, Ziva D; Rabin, Rachel A; George, Tony P. (2021). A systematic review and meta-analysis of sex differences in cannabis use disorder amongst people with comorbid mental illness.. The American journal of drug and alcohol abuse, 47(5), 535-547. https://doi.org/10.1080/00952990.2021.1946071