Letter to the Editor
About a year ago, we published a paper in Lancet Psychiatry regarding the associations between cannabis and other substance use disorders with mortality in people with severe mental disorders 2. The study was based on extensive, nationwide, unselected Danish registers. Interestingly, we found results that are in line with the conclusions of the review by Goyal and colleagues. Although cannabis use disorders generally increased all-cause mortality, albeit modestly, cannabis use disorder was significantly associated with a decreased risk for death from disorders related to digestive organs, with a subhazard ratio (similar to a hazard ratio, except that it is adjusted for deaths from other causes) in patients with schizophrenia of 0.44 (95% confidence interval: 0.28–0.68) (P=0.0002) when adjusting for other types of alcohol or illicit substance use disorders. In depression, the same pattern was observed, although it was not statistically significant [subhazard ratio 0.60 (95% confidence interval: 0.35–1.03), P=0.07]. In the original paper, we did not estimate this for the entire population, regardless of the presence of psychiatric disorders. However, we have repeated our analyses and found an adjusted hazard ratio for death from disorders of the digestive organs related to cannabis use disorder of 0.64 (95% confidence interval: 0.52–0.77) (P<0.0001).
It is our opinion that the role of cannabis and cannabinoids in treating and preventing disorders of the gastrointestinal system should receive increased attention from the research community and from the medicinal industry alike.