Dr. William Kroger, in Clinical and Experimental Hypnosis, Chapter 33, Hypnosis in Internal Medicine, citing 90 sources for this one chapter, reports on the use of clinical hypnosis for:

For many of the appropriate complaints, particularly the chronic ones, I can work with your patients as clients, with your referral. For surgical or life-threatening conditions, I will work only under your direct supervision.

Dr. Hans Selye, beginning in the 1920s, identified the changes to the body as a result of stress and the "fight or flight" response. The changes are referred to as the General Adaptive Syndrome and include suppression of the immune system.

In 1957, Dr. Bruno Klopfer reported on "Mr. Wright" and his experience with Krebiozen. "Mr. Wright", a patient with lymphosarcoma and a very strong belief that medical science would save him, had a remission when treated with Krebiozen. When news came out that the drug was not working, he had a relapse. The treating physician injected the patient with distilled water, telling him it was a stronger version of Krebiozen, and the patient once again had a remission. Several months later, amid lots of publicity, the FDA announced Krebiozen was worthless, and in a few days, "Mr. Wright" relapsed and died.

Drs. Holmes and Rahe of the University of Washington School of Medicine in 1973 published their Social Readjustment Rating Scale that identified quantified stress levels for more than forty life events. A total score of 150 was shown to predict a 50-50 chance of illness. A score of over 300 predicted a 90 percent likelihood of illness.

Drs. Friedman and Rosenman correlated behavior and cardiovascular disease in 1974 in the book Type A Behavior and Your Heart.

Dr. Vernon Riley took a strain mice of bred for susceptibility to cancer, and divided them into two groups, one in a stress-free environment, the other in a highly stressed environment. At the point 80 percent would have been expected to have contracted cancer, 92 percent of the highly stressed mice had. Of the unstressed mice, only 7 percent had. This showed that something beyond genetics and diet are involved in the expression of cancer.

Candace Pert, Ph.D., in multiple papers between 1973 and now, identified receptor sites for neuro-peptides on all types of cells from intestinal lining, to heart tissue, various parts of the brain, and even in muscle and immune cells. These discoveries provide an explanation of the mechanism of how perception and thought influence all parts of the body, even the individual immune cells.

In 1981, Dr. Robert Ader, University of Rochester School of Medicine, proved that immune cells "learn" to associate environmental conditions and health insults, and may produce the response to the environmental condition even in the absence of the insult.

Dr. Carl Simonton, in Getting Well Again, 1978, has shown that improved attitude and will to live has a positive correlation with longer life in cancer patients.