A major study into the effect of cannabis consumption on multiple sclerosis (MS) patients has concluded the drug makes no difference to the disease’s progression.
Scientists began investigating whether tetrahydrocannabinol (THC), one of the active ingredients in cannabis, could accelerate the onset of disability, after previous studies had suggested cannabis could slow the advance of MS.
During an eight-year period, 493 volunteers took capsules of THC and were monitored as part of the CUPID (Cannabinoid Use In Progressive Inflammatory Brain Disease) study, which was presented today at the Association of British Neurologists annual meeting.
Lead researcher, Professor John Zajicek, told the BBC he was “disappointed’ the overall effect was not better.
"There's lots of evidence cannabis has a symptomatic effect - it makes people's pain, muscle stiffness and spasms better," he said.
"But what we were doing in this trial was to see if we could slow down the course of the disease.
"There are very, very few treatments for any neuro-degenerative disease, whether it's Alzheimer's, Parkinson's or progressive multiple sclerosis and we were very much hoping cannabinoid might slow down the progression of the disease as opposed to just ameliorating people's symptoms.
"I'm very disappointed - not for me - but for people with MS and I think it's desperately important that we try to find treatments that slow their progression down."