SAM Friday Fact 06/14/2024: Nearly one-third of Canadians who consumed marijuana in the past 12 months reported experiencing at least one adverse health effect

The results of a survey of Canadians aged 16-65 who used marijuana in the last year were published in the study, “Adverse outcomes of cannabis use in Canada, before and after legalisation of non-medical cannabis: cross-sectional analysis of the International Cannabis Policy Study.” The survey aimed to find what percentage of these users experienced at least one adverse health effect due to marijuana. The respondents of the survey were given the option to select multiple symptoms that they experienced.

The study found that “approximately one-third of people who consume cannabis reported experiencing at least one adverse event within the past 12 months.” In 2021, the following percentage of past-year users experienced these symptom(s): 

  • Any adverse event: 29.9%
  • Panic reactions: 9.9% 
  • Feeling faint or dizzy or passing out: 7.9% 
  • Nausea and/or vomiting: 7.1% 
  • Cannabinoid hyperemesis syndrome in their lifetime: 5.8% 
  • Depression: 4.9% 
  • Lung or breathing problems: 4.8% 
  • Heart or blood pressure problems: 3.3% 
  • Hallucinations/psychosis: 2.8% 
  • Flashbacks: 2.6% 
  • Other: 2.4% 

The article stated: “Substantial proportions of people who consume cannabis report adverse events, suggesting widespread difficulty in ‘dosing.’”

If you have first-hand experience with any negative symptoms of marijuana or know someone that has been negatively affected by marijuana use, we strongly encourage you to submit a public comment to the Drug Enforcement Administration in opposition to their proposal to move marijuana from Schedule I to Schedule III. Click here to submit your public comment.