The American Academy of Neurology has published a new study that concludes medical marijuana is an effective treatment for several symptoms of multiple sclerosis (MS), including muscle spasms.
Previously, marijuana was shown to be effective in treating a number of general symptoms — including chronic pain and chemotherapy-induced nausea — but the research regarding its effect on MS-specific symptoms was mixed.
The new review, published today in the journal Neurology, looked at 34 studies on marijuana's effect on a range of neurological illnesses conducted over the past decade.
Most of the studies involving MS used medicinal marijuana in a pill or spray form. As a whole, they found that the drug was effective in treating several MS symptoms, including chronic pain, muscle spasms, and overactive bladder. The authors note that only two MS studies used smoked marijuana — both of which were inconclusive — and that the potential negative effects of marijuana on memory should make it a secondary option.
Still, the finding that it's an effective way of reducing spasms is promising, as many of the existing medicines that patients use to manage attacks cause significant side effects and are inconsistent in their effectiveness. Currently, most of the 21 states that allow doctors to prescribe marijuana list MS as one of the approved conditions, but the official review from the country's largest group of neurologists is likely to make doctors more willing to turn to the drug as an option.
The new review also looked at research involving the effectiveness of medical marijuana on a range of other neurological diseases — including Parkinson's, Huntington's, Tourette syndrome, and epilepsy — and determined that there's not yet enough evidence to determine if it's an effective way of treating these other conditions.