There have been many studies of the use of CAM in the general population. One well-known study identified the popularity of CAM and stimulated interest in the subject. This United States study, reported by Dr. David Eisenberg and others in 1997, found that about 40 percent of people used some form of CAM and that people visited unconventional medical practitioners more frequently than primary care physicians. Almost 20 percent of people were taking prescription medication along with some type of herb, vitamin, or other dietary supplement. Nearly one-half used CAM without the advice of a CAM practitioner or physician, and more than one-half (60 percent) did not discuss their use of unconventional medicine with their physician.

CAM use in people with MS appears to be greater than that in the general population. In studies in several countries, including the United States, Canada, the Netherlands, Germany, and Australia, it has been found that about one-half to three-quarters of people with MS use some form of unconventional medicine. In these studies, nearly all people with MS use unconventional medicine in conjunction with conventional medicine. In other words, the unconventional medicine is used as complementary medicine. Some of the CAM therapies that are more commonly used by people with MS include special diets, dietary supplements, prayer and spirituality, chiropractic medicine, and massage.