Doctors say there is enough evidence to warrant licensing cannabis treatment for multiple sclerosis (MS) following the biggest study into the use of cannabis to relieve symptoms of the disease.
Although there was no objective evidence that cannabis relieved spasticity, or muscle stiffness, caused by the disease, patients reported some improvements in pain relief, rigidity and mobility.
There were also fewer relapses in patients given cannabis capsules or extract than in MS sufferers taking a placebo, or dummy pill.
Some sufferers of MS, which affects about a million people worldwide, have reported that cannabis eases pain and muscle rigidity but Dr John Zajicek, a neurologist from the University of Plymouth, who headed the study, said there was very little evidence in the medical literature.
Earlier this year, The Netherlands became the world's first country to make cannabis available as a prescription drug for cancer, HIV and MS. Patients in Britain, Canada, Australia and the United Sates have pushed for similar measures.
British drug firm GW Pharmaceuticals has pioneered an under-the-tongue cannabis spray for MS patients that could be launched in Britain this year.