Adults with both cannabis and alcohol use disorders have a higher mortality risk than those with cannabis use disorder alone, according to results of a study published in Psychiatry Research.
To add to the data on individuals entering treatment for cannabis use disorder, the researchers conducted a follow-up study on 1136 individuals in Northern Italy who sought hospital, mental health, or substance abuse treatment services between 2009 and 2019 for cannabis use disorder. Individuals who used illicit drugs were excluded. Individuals were divided into either a cannabis-only or a cannabis-and-alcohol group. The researchers measured crude mortality rates per 1000 people (CMR) and standardized mortality ratios adjusted for age, sex, and calendar year (SMR).
Among patients with cannabis use disorder, the CMR was 4.37 per 1000 person years. The mortality rate of the general population is 2.24 per 1000 person years.
People with only cannabis use disorder had a higher survival rate than those with alcohol and cannabis use disorders. The survival rate was 98.28% (95% CI, 96.14%-99.24%) for the cannabis-only group and 89.87% (95% CI, 82.77%-94.14%) in the comorbid group. Tumors and suicide were the top 2 causes of death.
Patients with concomitant alcohol use disorder and cannabis use disorder saw higher CMR (10.2; 95% CI, 6.6-15.6) and SMR (12.29; 95% CI, 7.93-19.06) compared with patients with cannabis use disorder alone (CMR, 1.8; 95% CI, 0.9-36; SMR, 2.3; 95% CI, 1.1-4.5).
The small sample size limited the researchers’ ability to evaluate multiple causes of death. The researchers also didn’t have data on tobacco use, education, and professional status.
“Individuals with only cannabis use disorders have a lower mortality risk compared to those with both cannabis and alcohol use disorders,” the researchers concluded.
“Further studies to analyze the effects of the COVID-19 pandemic on the problematic consumption of cannabis and on the risk of death are needed.”
Pavarin RM. Mortality risk for individuals with cannabis use disorders in relation to alcohol use disorders: results of a follow-up study. Psychiatry Res. 2022;316:114741. doi:10.1016/j.psychres.2022.114741