Nearly 90% of MS patients using cannabis for bladder symptoms reported improvement | Research

The takeaway

Among 775 people with MS surveyed, 37.5% used cannabis, and those who used it had twice the odds of reporting improvement in urinary frequency, urgency, leakage, and bladder emptying.

MS patients with bladder symptoms, neurologists, and urologists treating MS-related bladder dysfunction.

89.5% of MS patients using cannabis for bladder symptoms reported improvement

What the researchers found

Of 734 respondents reporting cannabis use status, 275 (37.5%) used cannabis in the past 3 months, with 73.8% using at least weekly. Among 19 patients specifically using cannabis for bladder symptoms, 89.5% reported improvement. Cannabis use was associated with two-fold increased odds of reporting improvement in urinary frequency, urgency, bladder leakage and wetness, pad use, and bladder emptying. Top reasons for use: sleep (58.3%), pain (51.5%), relaxation (44.4%), muscle spasms (40.2%).

Why it matters

Bladder dysfunction affects up to 80% of MS patients and significantly impacts quality of life. While cannabis is commonly used by MS patients for other symptoms, its effects on bladder function have received little attention.

The numbers in context

775 respondents out of 2,899 contacted (26.7% response rate). 275 (37.5%) used cannabis. 73.8% used weekly or more. 78.1% cited medical/therapeutic reasons. 89.5% of those using for bladder symptoms reported improvement. 2x odds of improvement in multiple bladder outcomes.

How the study worked

Cross-sectional survey of people with MS recruited from the MS Clinic in Calgary, Alberta, Canada. 775 responded out of 2,899 contacted. Logistic regression assessed associations between cannabis use and bladder symptom improvement.

What this study cannot tell us

Self-reported outcomes. Low response rate (26.7%) introduces selection bias. Cross-sectional design. No dose standardization. Those who found cannabis helpful may have been more likely to respond.

How to read the evidence

Moderate sample from a single MS clinic. Self-reported outcomes and low response rate limit conclusions.

When this study was published

2021 survey from Calgary, Canada following recreational legalization.

The bigger picture

The endocannabinoid system has known roles in bladder function, providing biological plausibility for these findings. However, the self-reported nature of the data means placebo effects and selection bias cannot be ruled out.

Questions still open

Would controlled trials confirm the bladder benefits? Which cannabinoid (THC vs. CBD) drives the bladder effects? How does cannabis compare to standard MS bladder medications?

Common questions

How common is cannabis use among MS patients?

In this Canadian survey, 37.5% of MS patients reported using cannabis in the past 3 months, with nearly 74% using at least weekly. Most cited medical or therapeutic reasons.

Which bladder symptoms improved with cannabis?

Cannabis users reported improvement across multiple bladder measures: urinary frequency, urgency, leakage, wetness, pad use, and bladder emptying, each with approximately twice the odds of improvement compared to non-users.

Read the original research

Cannabinoids and bladder symptoms in multiple sclerosis.

Multiple sclerosis and related disorders, 54, 103105

View on PubMed ↗Publisher’s paper ↗

Citation

Kim-Fine, Shunaha; Greenfield, Jamie; Chaput, Kathleen H; Robert, Magali; Metz, Luanne M. (2021). Cannabinoids and bladder symptoms in multiple sclerosis.. Multiple sclerosis and related disorders, 54, 103105. https://doi.org/10.1016/j.msard.2021.103105