Marijuana enjoyers 22% more likely to need emergency care and hospitalization

The use of recreational marijuana is associated with increased emergency room visits and hospitalization, according to a new study from the University of Toronto.

The study, published Monday in the journal BMJ Open Respiratory Research, analyzed national health records data for 35,114 residents of Ontario, Canada, ages 12 to 65, between Jan. 2009 and December 2015.

Recreational and medical marijuana are legal across Canada.

Researchers found cannabis users were 22% more likely to visit an emergency department or be hospitalized.

The finding held after adjusting the analysis for 31 confounding factors, such as other tobacco smoking, substance abuse and problem drinking.

"Cannabis use is not as benign and safe as some might think," said study author Nicholas Vozoris,  assistant professor and clinician investigator within the Division of Respirology, Department of Medicine, at the University of Toronto.

"Our study demonstrates that the use of this substance is associated with serious negative outcomes, specifically, ED (emergency department) visits and hospitalizations," Vozoris said in an email to CNN.

This goal of the study was to examine the link, if any, between cannabis smoking and acute respiratory illness, as research in the area was “extremely limited.” The data found that respiratory-related reasons were the second-leading origin of all ED visits and hospitalizations among marijuana users.

The research contributes to a growing body of evidence that connect cannabis use with negative health outcomes, both physical and mental.

One study from 2021 found that heavy use of marijuana by teens and young adults with mood disorders, like depression and bipolar disorder, was associated with heightened risk of self-harm, suicide and mortality in those groups.

Another 2021 study found habitual cannabis users have been increasingly afflicted with severe stomach pain and nausea, a condition known as “cannabis hyperemesis syndrome.”

Legalizing recreational marijuana is attractive to U.S. states looking for new, lucrative sources of tax revenue. Most of the states that legalized recreational marijuana now raise more revenue from taxes on legal pot sales than alcohol sales and taxe.