World's biggest MS trial shows benefits of cannabis

Results from the world's largest study into the medical effects of cannabis have shown that the drug can reduce pain and improve the lives of people with multiple sclerosis.

Scientists concluded that patients for whom other treatments have failed should be given tablets made from cannabis derivatives.

The three-year study, published in the medical journal The Lancet today, is the first clinical appraisal of whether cannabis-derived drugs can help treat MS.

Mike O'Donovan, chief executive of the Multiple Sclerosis Society said: "These improvements to quality of life can make a significant difference to people with MS. On the evidence now available, the MS Society believes those who might benefit should be able to have treatment prescribed on the NHS."

Patients say that smoking the drug reduces symptoms such as muscle stiffness and tremors, and gives them greater mobility. Pharmaceutical companies are working urgently to develop drugs using cannabinoids, the natural chemicals found in cannabis which appear to soothe pain and alleviate muscle stiffness.

About 85,000 people suffer from MS in Britain, and it is the most common neurological disease affecting young adults in the Western world.

Researchers from the University of Plymouth tested more than 600 patients with MS, giving some of them cannabinoid tetrahydrocannabinol (THC) and the others a placebo. The groups were not told whether they were taking THC or the placebo.

When the researchers used standard clinical tests, they found little evidence that THC reduced muscle stiffness. But in interviews, 60 per cent of the THC patients said they had less muscle stiffness, compared with 46 per cent of the placebo group. Fifty-four per cent of the THC group said their pain was reduced, compared with 37 per cent of those taking the placebo. Twelve per cent of those on THC found it easier to walk a short distance, compared with 4 per cent of the other group.

Dr John Zajicek, the lead researcher, said: "Our findings provide some evidence that cannabinoids could be clinically useful in treatment of symptoms related to multiple sclerosis, but more work is necessary."

Professor Colin Blakemore, chief executive of the Medical Research Council which funded the study, said: "This work underlines the importance of funding large-scale clinical trials of possible treatments so the evidence can be weighed up."

A Department of Health spokeswoman said:"It is important to try to evaluate the claims on a proper scientific basis ... If the benefits of a cannabis-based medicine were to be scientifically demonstrated, the Government would be willing to amend the misuse of drugs controls to allow the prescribing of such a medicine."