Earlier this year, the Multiple Sclerosis Society of Canada joined the Canadian Institute of Health Research to provide $1.5 million in funding for research into how cannabis can be used to manage multiple sclerosis (MS) symptoms.
Evidence-based cannabis health research in MS is limited at best in Canada—given the plant’s previously illegal status—and across the world. Much remains unknown about the health and safety effects of using cannabis to treat MS and other diseases. New funding could help accelerate research, validate the potential therapeutic benefits of cannabis, and better understand its risks and harms.
What is Multiple Sclerosis?
Defined as “a chronic, often disabling disease of the central nervous system comprising the brain, spinal cord and optic nerve” by the MS Society of Canada, MS typically appears between the ages of 20 and 40 and affects approximately twice as many women as men. Canada has one of the highest rates of the disease in the world, with 11 Canadians diagnosed with MS every day, according to the society.
Symptoms develop as the disease progresses and commonly include pain, spasms, muscle spasticity, limb tremor, fatigue, depression, disrupted cognitive function, and bladder incontinence. “MS most frequently presents at onset as a relapsing and remitting disorder, where symptoms come and go,” says the National Multiple Sclerosis Society.
Using Cannabis to Treat Multiple Sclerosis
Current treatment is focused on managing common MS symptoms and slowing disease progression. It often comes with negative side effects, from dizziness and drowsiness to abdominal cramps, gastrointestinal changes, elevated heartbeat, changes in sex drive, and more.
This leads many people to seek alternative therapies—like cannabis. “Cannabinoids, the active ingredients in cannabis, have demonstrated the ability to control aspects of MS disease progression […] and can help manage such symptoms as pain, spasms, spasticity, and incontinence,” says the Americans for Safe Access. Cannabis has also been shown to have ‘neuroprotective effects’ during immune attacks on the central nervous system, common in people with MS.
Using cannabis to manage MS symptoms remains controversial, but a growing number of people in Canada and around the world are using it to treat the disease. A 2017 study (Cofield, S.S. et al.) of participants in the North American Research Committee on Multiple Sclerosis Registry found that over 90% of respondents had considered using cannabis to manage their MS, have used it for MS, or have spoken to their healthcare provider about its use.
Prior to that, a 2005 survey of MS patients in the United Kingdom found that 43% of respondents used cannabis therapeutically. Among them, 75% said that cannabis mitigated their spasms, and over 50% said it alleviated their pain.
It should also be noted that while non-medical cannabis is now legal in Canada (medical cannabis has been legal since 2001) the use of cannabis to treat disease is still highly regulated or prohibited in other countries.
For instance, in November 2018, the United Kingdom government legalized cannabis for medical use, but put strict criteria in place for who could access it. Updated rules are expected by October 2019. Comparatively, in 2015, Croatia legalized medical cannabis use, ruling that medicine containing THC can be prescribed to treat health problems associated with cancer, multiple sclerosis, epilepsy, and AIDS.
Common Cannabis Treatments
The most common types of cannabis product used to manage MS symptoms are:
- Oral cannabis extract and synthetic THC (Dronabinol and Nabilone): used to reduce spasticity, muscle stiffness and pain, and improve sleep quality.
- Oral dronabinol: a synthetic cannabis derivative reportedly used to help slow the progression of MS and protect the nervous system.
- Sativex® oral spray: contains Tetranabinex® and Nabidiolex® cannabis extracts and is used to treat spasticity. It has also been reported by the American Academy of Neurology to improve pain and urinary frequency.
As far as other forms of cannabis, according to the American Academy of Neurology, “smoked cannabis research studies have not [yet] proved enough evidence to assess its safety or effectiveness for treating MS symptoms […]” Research is expected to emerge in the coming years.
Adverse Effects of Cannabis
While using cannabis may not cause the same or as severe side effects as other MS treatments, “people with MS should be aware of potential adverse effects of cannabis products, including new or worsening cognitive symptoms, psychosis, tolerance and dependence, as well as drug-drug interactions,” researchers Michelle Cameron and Jessica Rice say. Other side effects may include dizziness, drowsiness, nausea, vomiting, dry mouth and eyes, increased appetite, elevated heart rate, and potential risk to the lungs if cannabis is smoked. The long-term safety of using cannabis to manage symptoms also remains unknown.
And while high-quality research on the topic is steadily growing—as it becomes easier to access legal cannabis and financial investment—there is still a need for standardization in methodology, consistent product availability, and sufficient quality control testing.
Leafly adds, “A significant amount of evidence suggests THC and CBD-based medications can be used for treating muscle spasticity associated with multiple sclerosis, but most studies have focused on synthetic derivatives. Few have examined whole-plant cannabis or many of the other MS associated symptoms.”
The MS Society of Canada agrees that more research is needed and many questions remain unanswered, like: Which symptoms are best treated with cannabis?; Which type of cannabinoid is best?; and How does dosage and method of consumption impact the efficacy of cannabis? Developing treatments is a top priority for the society.
Access to Medical Cannabis in Canada
Beyond developing treatments and expanding research, the MS Society of Canada remains concerned with Canadian’s access to affordable medical cannabis. The society supports the Canadians for Fair Access to Medical Marijuana initiative, which advocates that medical cannabis should be zero-rated and exempt from excise and sales taxes, in all its forms and potencies.
As research continues to emerge in Canada and beyond, MS patients are encouraged to talk with their healthcare team to discuss options in managing their MS symptoms, including the risks and benefits of using cannabis.