Since the publication of the first edition, there have been numerous trials of treatment conducted in many countries in an effort to find an effective therapy for MS. Several of these treatments have been reported to have a positive effect in reducing the frequency of attacks or in slowing progression in well-designed studies. This is a summary of new developments in the field of multiple sclerosis research and therapy, written by members of the Therapeutic Claims Committee, a group of physicians who deal with multiple sclerosis patients on a daily basis. Examples include plasmapheresis, alpha- and beta-interferon, copolymer I, total lymphoid irradiation and cyclophoshamide. Although the exact cause of MS remains unknown, encouraging progress has been made in understanding triggering factors and it is hoped that this will result in more effective preventive measures.