The Myth of the Placebo Effect

n 1955 Dr. Henry Beecher, an anesthesiologist at Harvard Medical School, published a landmark paper in the Journal of the American Medical Association, “The Powerful Placebo.” The article is remarkable for the claims it made, for its wide influence, and for its profound flaws. Beecher had been studying placebos — pharmacologically inert treatments, such as pills with no active ingredient — and reviewed evidence from fifteen clinical trials in which the effectiveness of real treatments to reduce subjective patient-reported outcomes, for instance pain, nausea, and anxiety, was tested by comparing them to placebos. Beecher concluded that, overall, in 35 percent of cases the condition was “satisfactorily relieved by a placebo,” which he took to be evidence of therapeutic effectiveness. He also discussed a few studies finding objective effects of placebos, such as the production of gastric acid and increased adrenal cortical activity. Because the effect seemed to occur more or less equally in a variety of conditions, Beecher inferred that “a fundamental mechanism in common is operating.”