A survey of Canadian multiple sclerosis patients indicated a rather widespread use of medical cannabis and a general perception of efficacy by users.
Among people with multiple sclerosis, cannabis use is significantly higher than in the general population, according to research data. The motivation lies in the beneficial effect of cannabis on some important symptoms of the disease, such as spasticity, chronic pain, fatigue, anxiety and depression, making it, in the eyes of patients, a viable alternative or complementary option to therapy.
With regard to cannabis for medical use, however, evidence of efficacy in the treatment of multiple sclerosis is still limited and does not allow definitive conclusions to be drawn in terms of benefits and adverse effects.
A group of researchers recently conducted a study to assess the prevalence of medical cannabis use, identify the most common symptoms for which it is used, and determine the frequency and severity of adverse events in patients with multiple sclerosis in Canada, where the use of cannabis for medical use was legalised in 2001.
The survey conducted in Canada
For the cross-sectional study, an anonymous questionnaire was used to collect information on participants’ characteristics and disease, quality of life and cannabis use.
In the case of multiple sclerosis, the information obtained from the questionnaire concerned the clinical diagnosis, the time elapsed between the onset of symptoms and the diagnosis, current therapies, and the degree of disability assessed by means of the PDDS (Patient Determined Disease Steps) scale, a validated tool for measuring this patient-reported outcome. Another validated instrument, the MSQOL-54 (Multiple Sclerosis Quality of Life-54) was used to assess health-related quality of life.
The questionnaire was offered to 459 patients, and 344 complete answers were collected and analysed.
What the results suggest
The participants were overwhelmingly female (80 per cent), with an average age of 49 years; 79 per cent had a relapsing-remitting form of multiple sclerosis and slightly more than half (52.3 per cent) claimed to be using medical cannabis at the time of completing the questionnaire, while 10.2 per cent had used it at least once in the past. The remainder (37.5%) had never tried it; the main reasons for this were lack of knowledge of the potential benefits (in 34.4% of cases), perceived lack of need or lack of interest (15%) and social stigma (14.4%). Former users cited cost and lack of accessibility (in 34.4 per cent of cases), perceived ineffectiveness of treatment (28.6 per cent) and adverse effects (17.1 per cent) as reasons for discontinuing treatment.
Among people who used or had used medical cannabis in the past, the main symptoms treated were sleep disorders (84.1%), pain (80%), spasticity (68.4%), stress (66.5%) and fatigue (59%), while the most frequently reported adverse effects were drowsiness (57.2%), a feeling of stillness/submission (48.8%), difficulty in concentrating (28.4%), balance problems (22.3%) and incoherent thoughts (17.7%).
More than 80 per cent of the participants using medical cannabis at the time of the survey rated it as effective or highly effective for treating spasticity, pain, sleep disorders, bad mood and stress; for between 50 and 80 per cent of patients, efficacy was also seen in the treatment of anxiety, headache and fatigue. The perception of effectiveness was higher in current users than in former users.
Analysis of the data on disease characteristics and quality of life showed that, compared to the non-user group, there were more patients with progressive or more severe forms of multiple sclerosis and worse quality of life among current and former medical cannabis users.
“The data collected indicate that nearly 2 out of 3 participants with multiple sclerosis have tried medical cannabis at least once, and that the likelihood of trying it is higher in individuals with more severe forms of the disease”, the research authors comment. “Moreover, in the perception of consumers, the treatment proved effective for several symptoms, with adverse effects generally not serious and not decisive for eventual discontinuation. The results support the need for further research on the use of medical cannabis in multiple sclerosis and wide dissemination of the findings”, the researchers conclude.
Reference
Santarossa TM, So R, Smyth DP, et al. Medical cannabis use in Canadians with multiple sclerosis. Mult Scler Relat Disord. 2022;59:103638.