London A marijuana pill appeared to relieve some of the symptoms of multiple sclerosis in the first scientifically rigorous study of the strongly debated drug.
The research, published this week in The Lancet medical journal, found that even though improvements could not be detected by doctors' tests, a greater proportion of patients taking the drug reported reduced pain and muscle stiffness than those taking fake capsules.
Experts said the mixed results made them tricky to interpret. Some said they were encouraged any improvement was noted, while others said if there had been a major effect, it would have shown up in the doctors' tests.
One study leader, Dr. John Zajicek of the University of Plymouth in England, said the research raised questions about what was more important: a doctor's measurements or the patient's perspective.
"I think if there's a conflict, it's what the patient feels which is important, so I think it's quite encouraging," said Roger Pertwee, a professor of neuropharmacology at University of Aberdeen, who was not connected with the study.
Multiple sclerosis, a nervous system disease, causes a range of chronic symptoms, including muscle stiffness and spasms, pain and tremor.
It is difficult to study because the disease is unpredictable and its symptoms hard to measure.
Orthodox treatments often provide inadequate relief, so many MS sufferers experiment with alternatives, including cannabis and its major active components -- cannabinoids.
The study was set up to test the theory that cannabis -- the Latin word for marijuana -- and cannabinoids reduce muscle stiffness and may help alleviate other MS-related symptoms.
It involved 630 multiple sclerosis patients in Britain. One-third received a capsule containing whole cannabis oil; another third took one containing a synthetic version of a cannabinoid known as tetrahydrocannabinol, or THC. The rest received a fake capsule.
"The stiffness as you move the limb on the bed and measure it carefully does not pick up a difference," said one researcher, Dr. Alan Thompson. "But when you look at the impact that (muscle stiffness) has on everyday life -- on what the patient feels -- then there is a difference."