How effective is cannabis for multiple sclerosis symptoms?

MS is the indication with the strongest clinical evidence for cannabis, particularly for spasticity and neuropathic pain. Nabiximols (Sativex — 1:1 THC:CBD oromucosal spray) is approved in 30+ countries for MS spasticity. A 2012 Cochrane review of 12 RCTs found cannabinoids significantly reduced patient-reported spasticity (NRS) and pain, though objective spasticity measures (Ashworth scale) showed smaller effects. The 2014 MUSEC trial (n=279) found oral cannabis extract reduced muscle stiffness and pain vs. placebo. For bladder dysfunction (overactive bladder, nocturia) — a major MS symptom — nabiximols showed significant benefit in the CAMS trial. Limitations: most trials are short-term (≤12 weeks); long-term safety data in MS patients is limited; cognitive effects are a concern given existing MS-related cognitive impairment.