Rates, characteristics and manner of cannabis-related deaths in Australia 2000-2018.
Level 4 - case-series / case-control
Retrospective case series of medicolegal coronial files without a control group
PubMed 32370933 · doi:10.1016/j.drugalcdep.2020.108028
What was done
Retrospective case review of Australian medicolegal files from the National Coronial Information System (NCIS) spanning July 1, 2000, to December 31, 2018. The study analyzed rates, demographic characteristics, toxicological findings, and manner of death for all identified cannabis-related fatalities.
What was found
A total of 559 cases were identified (mean age 35.8 years, 81.2% male). The crude mortality rate per 100,000 people ranged between 0.10 (CI = 0.06-0.15) and 0.23 (CI = 0.17-0.30). Zero deaths were due solely to cannabis toxicity. Manners of death were: - Accidental injury: 29.9% (motor vehicle accidents were the leading cause; men were three times as likely to die of accidental injury than women) - Suicide: 25.0% - Polysubstance toxicity: 17.0% - Natural disease: 16.1% (cardiovascular 14.3%, respiratory 9.7%) - Natural disease and drug effect/toxicity: 7.9% - Assault: 3.0% - Unascertained: 1.1% Median blood Δ-9-tetrahydrocannabinol (THC) concentration was 0.008 mg/L (range 0.0005-19.00 mg/L). Other drugs were cited alongside cannabis in 81.4% of deaths, most commonly alcohol (47.2%).
Why it matters
This provides the first national overview of cannabis-related deaths in Australia, demonstrating that mortality associated with cannabis predominantly involves trauma, suicide, and polysubstance interactions rather than direct toxic effects.
Limits
The study is an uncontrolled retrospective series, preventing causal attribution of cannabis use to death. Polysubstance involvement was present in 81.4% of cases, confounding any single-substance effect. Toxicological detection of THC indicates prior exposure but does not prove acute impairment at the time of death, and coronial reporting practices varied over the 18-year period.
Cited by
- supports No fatal overdose deaths have been documented solely from the toxic effects of consuming THC.