Medical cannabis use in Canadians with multiple sclerosis.

Background: The extent of medical cannabis use by people with multiple sclerosis (MS) in Canada has not been evaluated for more than a decade since recreational cannabis was legalized. Legalization provided an avenue for those to whom legal cannabis was previously inaccessible to access it as an alternative therapy. Our objective was to evaluate the prevalence of medical cannabis use by Canadians with MS, the reasons it is used, adverse effects, as well as the context surrounding how it is obtained and where users learned about it.