People Hospitalized for Cannabis Use Disorder Had Nearly 3x the Death Risk Over 5 Years

Within 5 years of incident hospital-based CUD care, 3.5% of individuals died compared to 0.6% of matched general population members. After adjusting for comorbid conditions, CUD patients had 2.79 times higher death risk overall, with particularly elevated risks for suicide (9.7x), trauma (4.55x), opioid poisoning (5.03x), other drug poisonings (4.56x), and lung cancer (3.81x).

Population-based retrospective cohort study of all Ontario residents aged 15-105 (n=11.6 million) from 2006-2021, comparing mortality between 106,994 individuals with incident hospital-based CUD care and age/sex-matched general population members using cause-specific hazard models adjusted for comorbidities.

This is one of the largest studies to quantify mortality risk associated with cannabis use disorder severe enough to require emergency or hospital care. The findings suggest CUD is a marker for serious health vulnerability, even after accounting for other mental health and substance use conditions.

While CUD carried lower mortality risk than alcohol (1.30x), stimulant (1.69x), or opioid (2.19x) use disorders, the nearly threefold elevation over the general population challenges the perception of cannabis as relatively harmless. This study adds to growing evidence that severe CUD carries significant health consequences.

Only captures individuals severe enough to present to emergency departments or hospitals, not all people with CUD. Cannot establish whether cannabis use itself causes the elevated mortality or whether CUD is a marker for other risk factors. Comorbid substance use may confound results despite statistical adjustment.