Can Cannabis Use Lead to Suicidal Thoughts?

Cannabis use may be associated with suicidality trends among young adults, regardless of their depression status, according to a survey study.

An analysis of data from the National Surveys on Drug Use and Health (NSDUH) showed increases in suicidal ideation, plan, and attempt ranging from 40% to 60% over the past decade — increases beyond those attributable to either cannabis use or major depressive episodes (MDE) alone, reported Beth Han, MD, PhD, MPH, of the National Institute on Drug Abuse in Bethesda, Maryland, and colleagues.

Comparing the start of the study period (2008-2009) to the end (2018-2019) revealed an adjusted risk ratio of 1.4 (95% CI 1.3-1.5) for suicidal ideation, 1.6 (95% CI 1.5-1.9) for suicide planning, and 1.4 (95% CI 1.2-1.7) for suicide attempt, after controlling for MDE, cannabis use disorder (CUD), cannabis use status, and other potential confounding factors, the group noted in JAMA Network Open.

Data collected from over 280,000 young adults ages 18 to 34 also showed that a wide range of cannabis consumption — from CUD to non-daily cannabis use — was associated with a higher prevalence of suicidal thoughts and behaviors among both men and women, though it was more significant in women.

Among respondents without MDE, the prevalence of suicidal ideation in women with and without CUD was 13.9% and 3.5%, respectively. These rates were 9.9% and 3%, respectively, among men (P<0.001). Women diagnosed with both CUD and MDE were found to have a rate of suicide planning that was 52% higher (23.7%) compared with men with CUD and MDE (15.6%; P<0.001).

Contextually, young adults have seen general increases across the board in CUD, near-daily cannabis use, MDE diagnoses, and thoughts of suicide since 2008, the authors noted. The number of adults ages 18 to 34 who died by suicide from 2008 to 2019 also increased, by 51.9% for women (from 1,569 to 2,384) and by 44.9% for men (from 7,266 to 10,529), according to recent CDC data.

“Although adults with suicidality and adults who die by suicide can be interrelated yet distinct groups, our results are consistent with a possible role for cannabis use and CUD associated with the relatively higher percentage increase in deaths by suicide among women than men,” Han and colleagues wrote.

Of note, high school students who reported daily cannabis intake were the only sociodemographic subgroup that did not see an increase in suicidal ideation and plan.

The NSDUH — using a stratified, multi-stage area probability sample designed to be representative of each state — collected data through face-to-face household interview surveys conducted by the Substance Abuse and Mental Health Services Administration. Of the 281,650 adults ages 18 to 34 sampled from the 2008-2019 NSDUH, 50.1% were women and 49.9% were men.

The results “suggest that adults with MDE may be particularly vulnerable to cannabis use as beliefs in its therapeutic potential become more widespread and products become more accessible,” the authors warned. Still, they noted that “depression and cannabis use are associated with suicidality but do not appear to be the only causes for the upward trends in suicide among young adults.”

Han and colleagues acknowledged that use of the NSDUH brought a variety of limitations to their study, including the survey’s inability to account for people experiencing homelessness who are not living in shelters, those on active duty in the military, and institutionalized populations. The authors called for further research to be conducted using longitudinal data in order to examine and confirm their study’s findings.

If you or someone you know is considering suicide, call the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).