Cannabis Use Predicted Suicidal Thoughts in Men, While Suicidal Thoughts Predicted Cannabis Use in Women

In a large longitudinal study, daily cannabis use was associated with a 4-fold increased risk of developing suicidal thoughts in men, while suicidal thoughts predicted new cannabis use in women, revealing sex-specific directional relationships.

Shalit, Nadav et al.·Journal of affective disorders·2016·Strong EvidenceLongitudinal Cohort
RTHC-01263Longitudinal CohortStrong Evidence2016RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Longitudinal Cohort
Evidence
Strong Evidence
Sample
N=963

What This Study Found

Using data from over 30,000 participants followed over 3 years, researchers found strikingly different patterns between men and women in the cannabis-suicidality relationship.

In men, cannabis use predicted the development of new suicidal ideation. Any cannabis use nearly doubled the risk (AOR = 1.91), and daily use increased the risk more than 4-fold (AOR = 4.28). This association was not found in women.

The direction reversed for women: baseline suicidal ideation predicted the initiation of cannabis use (AOR = 2.34). Women who were already experiencing suicidal thoughts were more likely to start using cannabis, while this pattern was not found in men.

Neither direction showed a significant association with actual suicide attempts in either sex.

Key Numbers

Men: any cannabis use AOR = 1.91 (1.02-3.56) for suicidality. Daily use AOR = 4.28 (1.32-13.82). Women: baseline suicidality AOR = 2.34 (1.42-3.87) for cannabis initiation. Over 30,000 participants followed for 3 years.

How They Did This

Longitudinal population-based study using Waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Bidirectional analyses were conducted separately by sex. Cannabis users (n=963) were compared with non-users (n=30,586), and suicidal individuals (n=1,805) were compared with non-suicidal individuals (n=25,729). Multivariate logistic regression controlled for multiple covariates.

Why This Research Matters

This is one of the first studies to examine sex differences in the cannabis-suicidality relationship bidirectionally. The finding that the direction of the relationship is opposite in men and women has important clinical implications: in men, cannabis use may be a risk factor for developing suicidal thoughts, while in women, suicidal thoughts may drive cannabis use as a form of self-medication.

The Bigger Picture

The relationship between cannabis and mental health is often discussed as a simple cause-and-effect. This study demonstrates that the direction of causality may depend on sex, with cannabis potentially worsening mental health in men while women may turn to cannabis as a response to pre-existing mental health difficulties. This has implications for how clinicians screen and intervene.

What This Study Doesn't Tell Us

Suicidality was assessed only in individuals who reported depressed mood or anhedonia, potentially missing cases in non-depressed individuals. The wide confidence intervals for daily cannabis use in men (1.32-13.82) reflect relatively few daily users with suicidality outcomes. Observational data cannot prove causation even with longitudinal design. Self-reported cannabis use may be underreported.

Questions This Raises

  • ?What biological or psychosocial mechanisms explain the sex difference?
  • ?Does treating depression or suicidality in women reduce their likelihood of initiating cannabis use?
  • ?Would the male association hold after controlling for other substance use more thoroughly?

Trust & Context

Key Stat:
Daily cannabis use was associated with 4.28x increased risk of developing suicidal thoughts in men.
Evidence Grade:
Strong evidence from a large, nationally representative longitudinal study with bidirectional analysis and appropriate statistical controls.
Study Age:
Published in 2016 using NESARC data. The sex-specific nature of the cannabis-suicidality relationship continues to be studied.
Original Title:
The association between cannabis use and suicidality among men and women: A population-based longitudinal study.
Published In:
Journal of affective disorders, 205, 216-224 (2016)
Database ID:
RTHC-01263

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Follows a group of people over time to track how outcomes develop.

What do these levels mean? →

Frequently Asked Questions

Does cannabis cause suicidal thoughts?

In this study, daily cannabis use was associated with a 4-fold increase in developing suicidal thoughts among men over 3 years. However, the study cannot prove causation, and the association was not found in women, where the relationship ran in the opposite direction.

Why is the relationship different for men and women?

The study documented the pattern but did not explain the mechanism. One possibility is that cannabis affects mood differently by sex, or that men and women have different reasons for using cannabis (self-medication vs. social/recreational). More research is needed to understand the underlying biology.

Read More on RethinkTHC

Cite This Study

RTHC-01263·https://rethinkthc.com/research/RTHC-01263

APA

Shalit, Nadav; Shoval, Gal; Shlosberg, Dan; Feingold, Daniel; Lev-Ran, Shaul. (2016). The association between cannabis use and suicidality among men and women: A population-based longitudinal study.. Journal of affective disorders, 205, 216-224. https://doi.org/10.1016/j.jad.2016.07.010

MLA

Shalit, Nadav, et al. "The association between cannabis use and suicidality among men and women: A population-based longitudinal study.." Journal of affective disorders, 2016. https://doi.org/10.1016/j.jad.2016.07.010

RethinkTHC

RethinkTHC Research Database. "The association between cannabis use and suicidality among m..." RTHC-01263. Retrieved from https://rethinkthc.com/research/shalit-2016-the-association-between-cannabis

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.