Cannabis use disorder marks a higher risk of death

Design

Matched cohort study, single health system (observational)

Population

100,140 people aged ≥12; 16,693 with cannabis use disorder

Primary outcome

All-cause, injury-related and illness-related mortality over a median 7.7 years

Effect

All-cause HR 1.52 (1.30–1.77); overdose 2.59; injury 1.91; cancer 1.71

A matched cohort from a Colorado health system followed 16,693 people with a cannabis use disorder diagnosis and 83,447 without, over a median 7.7 years, using state death records.

Cannabis use disorder was associated with higher all-cause mortality (adjusted hazard ratio 1.52), and with death from injury (1.91), drug overdose (2.59), accidents (1.96) and cancer (1.71). It was not associated with death from self-harm, cardiovascular or respiratory disease. The pattern — injury and overdose rather than organ disease — fits a marker of broader risk rather than a direct toxic effect.

The practical use is as a flag. A recorded cannabis use disorder should prompt a wider look: screening for other substance use, overdose-risk counselling and naloxone where opioids are also in play, and attention to injury risk — not a conclusion that cannabis itself caused these deaths.

• Cannabis use disorder was linked to about a 50% higher all-cause mortality rate.
• The excess was in injury, overdose and accidents, not cardiovascular or respiratory death.
• Treat a cannabis use disorder diagnosis as a prompt to screen for other substance use and injury risk.
• Offer overdose counselling and naloxone where opioids are also involved.

Why it matters

It reframes an often-dismissed diagnosis as a signal worth acting on, chiefly for injury and overdose risk.

Don't overread it

This is observational: cannabis use disorder marks higher risk but the study cannot show it caused these deaths, and confounding by other substance use is likely.

The statistics, in plain English

A hazard ratio of 1.52 with an interval of 1.30–1.77 is a firm association, but association is not causation — the people with and without the diagnosis differ in many ways the adjustment cannot fully capture.

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