More than half of Canadians with multiple sclerosis (MS) report using cannabis to help manage their symptoms, according to a new study.

The study, “Medical cannabis use in Canadians with multiple sclerosis,” was published in Multiple Sclerosis and Related Disorders.

Humans have used the cannabis plant for millennia, both as a recreational intoxicant and as a medicine. Although its potential benefits for MS remain unproven, emerging research suggests it can help reduce spasticity, improve sleep, and ease pain.

Medical cannabis use was legalized in Canada in 2001. Recreational use was legalized nationwide nearly two decades later in 2018.

A research team led by scientists at the University of Alberta conducted an anonymous survey to assess cannabis use among Canadians with MS. The team noted that similar studies have been done in years past, but not since its recreational use was legalized, which made it more accessible for many.

“This cross-sectional study aimed to evaluate the prevalence of cannabis use in people with MS in Canada, its perceived efficacy in treating a variety of symptoms, and the frequency and severity of adverse effects [side effects]. Importantly, this has not been evaluated in Canada since recreational cannabis was legalized in 2018, although somewhat comparable studies were published in 2003 and 2004,” the researchers wrote.

“Given that cannabis has therapeutic promise in managing MS symptoms, it is essential to learn about current patient experiences to inform future research endeavors to develop effective alternative therapeutic regimens of symptom management aiming to improve quality of life,” they said.

The survey was answered by 344 Canadians with MS. Nearly 80% had relapsing-remitting disease, while the rest either had progressive forms or were unsure of their MS type. More than three-quarters of respondents identified as female, and the average age was about 45 years.

More than half (52.3%) of the respondents said they currently used cannabis to help manage symptoms. Another 10.2% said they had used medical cannabis, but were not current users.

Users, non-users, and former users did not differ significantly in terms of age, sex, or time spent living with MS. Compared to patients who had never tried it, current or former users were more likely to have progressive types of MS, tended to report more severe disability and worse quality of life, and were less likely to be on a disease-modifying treatment.

“We found that about two-thirds of participants reported having used medical cannabis to manage their MS symptoms, with those who have tried medical cannabis living with a greater disease burden than non-users,” the researchers wrote.

Among current users, the vast majority (73.8%) used it daily. The respondents reported using a range of products, including smoked or vaporized dried flower, concentrates (e.g., sublingual oil droppers or sprays), and ingestible forms (“edibles”).

The most common symptoms that patients reported using cannabis for were sleep problems (84.1%), pain (80%), muscle spasms (68.4%), stress (66.5%), and fatigue (59%).

The most common side effects associated with cannabis use included drowsiness (57.2%), feeling quiet or subdued (48.8%), difficulty concentrating (28.4%), balance problems (22.3%), and incoherent thoughts (17.7%). Most patients who reported having any of these effects said that they did not experience them a lot.

More than 80% of users said cannabis was effective for managing spasticity, pain, sleep problems, bad mood, and stress. More than half of users agreed it can help with anxiety, fatigue, and headache. Nearly all users noted it can stimulate an appetite.

“These patient-reported findings may inform future research into the efficacy of cannabis to treat the symptoms of MS,” the scientists wrote.

Current users tended to report that cannabis was more effective for them than former users did. Among former users, the most common reasons for stopping were cost and problems getting it (34.4%), followed by feeling it was not effective (28.6%) and having unwanted effects (17.1%).

Among those who had never used cannabis, the most common reasons given were being unaware of potential benefits (34.4%), being uninterested or feeling it was unnecessary (15%), and concerns around social stigma (14.4%).

The researchers noted that most users learned about cannabis from friends or their own research online, rather than from discussions with a healthcare provider.

“Many people with MS learn about cannabis on their own, which underscores a need for evidence-based resources to be readily available and updated to inform those exploring medical cannabis use for MS and to encourage them to engage in discussions with their healthcare team,” they wrote.

Overall, the results show that more research into the potential benefits of cannabis in MS is needed, the team concluded.