THE POWER OF NONSPECIFIC EFFECTS IN HEALING - IMPLICATIONS FOR PSYCHOSOCIAL AND BIOLOGICAL TREATMENTS

We evaluate the hypothesis that the power of nonspecific effects may a ccount for as much as two thirds of successful treatment outcomes when both the healer and the patient believe in the efficacy of a treatmen t. Five medical and surgical treatments, once considered to be efficac ious by their proponents but no longer considered effective based upon later controlled trials, were selected according to strict inclusion criteria. A search of the English literature was conducted for all stu dies published for each treatment area. The results of these studies w ere categorized, where possible, into excellent, good, and poor outcom es. For these five treatments combined, 40 % excellent, 30 % good, and 30 % poor results were reported by proponents. We conclude that, unde r conditions of heightened expectations, the power of nonspecific effe cts far exceeds that commonly reported in the literature. The implicat ions of these results in evaluating the relative efficacy of biologica l and psychosocial treatments is discussed.