A 2018 systematic review examined randomized controlled trials pertaining to the symptoms with the strongest evidence base, including 2 that are relevant to MS: pain and spasticity.4 The authors found that patients taking cannabinoids were more likely to achieve pain reduction of at least 30%, with a risk ratio of 1.37 (95% CI, 1.14-1.64) and number needed to treat of 11. Most studies investigating the effects of cannabinoids on pain focused on neuropathic pain. In addition, a positive global impression of change in spasticity was observed (risk ratio 1.45; 95% CI, 1.08-1.95; number needed to treat=7). These specific benefits are recognized by the American Academy of Neurology as having strong supporting evidence.5
There is also “indirect evidence that reductions in spasticity, pain, and fatigue may result in improvements in the mobility of [people with] MS,” according to another recent paper.3 The authors further noted that cannabis use has been shown to reduce the intake of prescription drugs that have more numerous and serious side effects, including opioids, benzodiazepines, and antidepressants. Findings published in 2017, for example, demonstrated that 77% of frequent opioid users had reduced consumption since initiating cannabis use, and many patients also decreased their use of antianxiety (72%), migraine (67%), and sleep-promoting (65%) medications.