Cannabis, COVID-19 And Hospitalization

Whether and how cannabis use affects COVID-19 outcomes has been the topic of much debate. This latest study shows consensus is still some way off.

Research published in late December last year suggested cannabinoids have the potential to limit susceptibility to and severity of COVID-19 infections, and some earlier research backs theories of symptom severity reduction.

But a new study out of Washington University School of Medicine in St. Louis challenges this, finding cannabis users are nearly twice as likely to required hospitalization and intensive care when experiencing COVID-19.

The finding is based on analysis of the health records of 72,501 people presenting with COVID-19 at health centers in a major Midwestern health-care system between February 1, 2020 and January 31, 2022. The analysis found patients who reported using cannabis at least once in the year preceding developing COVID-19 (7;060 patients – 9.7%) were 80% more likely to be hospitalized and 27% more likely to be admitted to the ICU than those without this history – comparable with the impact from tobacco smoking.

However, use of cannabis wasn’t associated with an increase in all-cause mortality following COVID-19.

“For the risk of death, tobacco risk is clear but more evidence is needed for cannabis,” said the study’s senior author Li-Shiun Chen, MD, DSc.

In the paper, the researchers concluded:

“The findings of this cohort study suggest that cannabis use may be an independent risk factor for COVID-19–related complications, even after considering cigarette smoking, vaccination status, comorbidities, and other risk factors.”

But given the cannabis use question just required a “yes/no” answer, what’s not clear is if there are differences in outcomes between different forms of cannabis – for example, smoking vs. consuming edibles or oils.

“Those are questions we’d really like the answers to,” said the study’s lead author Nicholas Griffith, MD. “I hope this study opens the door to more research on the health effects of cannabis.”

As with the other studies suggesting some protective/symptom severity reduction, this latest study has its share of acknowledged limitations. The research has been published in the journal JAMA Network Open.

While the world would like to put COVID-19 in its rear-view mirror, it is still common today. To date, there have been more than 704,753,890 infections and 7,010,681 deaths according to statistics from Worldometers. The real infection total would likely be far higher; particularly as testing and reporting has plummeted since the height of the pandemic.