Cannabis Use Disorder and Mortality Risk: A Matched Cohort Study from a Colorado Health System

Cannabis use disorder (CUD) is an underrecognized consequence of cannabis use, and evidence on mortality risk and leading causes of death among individuals with CUD remains limited.

To characterize all-cause and cause-specific mortality following CUD diagnosis and compare mortality risk between individuals with and without CUD.

This matched cohort study consisted of 100,140 individuals aged 12 years or older from a Colorado health system between 2006 and 2024, including 16,693 with a CUD diagnosis and 83,447 individuals without CUD, with follow-up through June 2024.

Primary outcomes were all-cause mortality, injury-related mortality, and illness-related mortality identified from state vital records. Secondary outcomes included deaths from drug overdose, self-harm, accidents, cancer, cardiovascular diseases, and respiratory diseases. Cox proportional hazards regressions estimated adjusted hazard ratios (HRs) and 95% CIs.

Over a median follow-up of 7.7 years, 1,197 (7.2%) individuals with CUD died. Compared to matched individuals, those with CUD had higher crude rates of all-cause mortality (899.5 vs. 374.6 per 100,000 person-years), injury-related mortality (295.3 vs 62.5 per 100,000 person-years), and illness-related mortality (604.2 vs. 312.1 per 100,000 person-years). In adjusted analyses, CUD was associated with increased risk of all-cause mortality (HR 1.52; 95% CI, 1.30-1.77), injury-related mortality (HR 1.91; 95% CI, 1.37-2.67), and illness-related mortality (HR 1.40; 95% CI 1.17-1.67). Among leading causes, CUD was associated with elevated mortality risk from drug overdose (HR 2.59; 95% CI, 1.30-5.19), accidents (HR 1.96; 95% CI, 1.01-3.80), and cancer (HR 1.71; 95% CI, 1.20-2.46), but not self-harm (HR 1.18; 95% CI 0.62-2.24), cardiovascular diseases (HR 1.25; 95% CI 0.87-1.81), or respiratory diseases (HR 1.29; 95% CI, 0.73-2.25).

CUD may serve as a marker of increased all-cause, injury-related, and illness-related mortality risk. Comprehensive prevention strategies are needed to address elevated mortality risk in individuals with CUD.