Effect of dronabinol on progression in progressive multiple sclerosis (CUPID): a randomised, placebo-controlled trial.

Background: Laboratory evidence has shown that cannabinoids might have a neuroprotective action. We investigated whether oral dronabinol (Δ(9)-tetrahydrocannabinol) might slow the course of progressive multiple sclerosis.

Methods: In this multicentre, parallel, randomised, double-blind, placebo-controlled study, we recruited patients aged 18-65 years with primary or secondary progressive multiple sclerosis from 27 UK neurology or rehabilitation departments.