Associations of Cannabis and Tobacco Use With Suicide Attempt, Suicide Death, and Overdose Death Among Veterans Prescribed Opioid Analgesics.

INTRODUCTION

Little is known whether cannabis and tobacco use are indicators of suicide-related risks. This longitudinal study examined the associations of cannabis and tobacco use with risks of suicide attempt/death and overdose death over a 2-year follow-up in a cohort of veterans prescribed opioids.

METHODS

This study analyzed data in 2024 using a national cohort of 923,291 veterans receiving opioid analgesics in Veterans Health Administration clinics collected during 2014-2019. Cannabis and tobacco use were assessed at cohort entry. Outcomes (suicide attempts, suicide death, overdose death) were obtained at follow-up through 2021. Cause-specific hazard models were used to examine the associations of cannabis and tobacco use with each outcome, adjusting for well-established risk factors for suicide/overdose (e.g., substance use disorders, mental health, sociodemographics).

RESULTS

At baseline, 5.4% of the cohort used cannabis, and 39.4% used tobacco. At the end of follow-up (median follow-up time of 6.7-6.8 years), 2.2% of the sample had attempted suicide, 0.4% had died by suicide, and 0.5% had died by overdose. In adjusted models, cannabis use was associated with a higher rate of suicide attempt (hazard ratio=1.11, 95% CI=1.06, 1.15). Current use of tobacco at baseline (versus never use) was associated with a higher rate of suicide attempts (hazard ratio=1.18, 95% CI=1.13, 1.22), suicide deaths (hazard ratio=1.19, 95% CI=1.07, 1.32), and overdose deaths (hazard ratio=1.67, 95% CI=1.51, 1.83).

CONCLUSIONS

Cannabis and tobacco use were associated with suicide attempts/deaths and overdose deaths among veterans prescribed opioid analgesics, underscoring a need for monitoring patients who use tobacco and cannabis in this population.