THE PLACEBO EFFECT AND EXPERIMENTATION ON HUMANS.

THE PLACEBO EFFECT AND EXPERIMENTATION ON HUMANS. Annalisa in her comment on THE LUCK OF RONALD REAGAN said, “I’m sure someone somewhere has done studies about good luck charms ‘working’ thanks to the placebo effect.” My brother Elmer also asked recently what was known about the placebo effect. One of the main arguments for insisting on controlled experiments on new drugs is the importance of the placebo effect. By this time, with so many studies having been done, there should be quite a bit of information available about placebo effects. For example, if it varies, why does it vary? Does the presentation by the doctor conducting the experiments make a difference? One might even expect that some predictions could be made about what the placebo effect would be in a given experiment. If not, it is hard to see how the placebo effect is different from random variation. This Wikipedia article about the placebo effect seems to say that the main conclusion is that it’s all very complicated. “Recent research [19] strongly indicates that a “placebo response” is a complex psychobiological phenomenon, contingent upon the psychosocial context of the subject, that may be due to a wide range of neurobiological mechanisms (with the specific response mechanism differing from circumstance to circumstance).” The section in the article on ethical challenges and concerns raises some of the issues that trouble me about insisting on controlled experiments. It includes the World Medical Association announcement in 2002 that “a placebo-controlled trial may be ethically acceptable, even if proven therapy is available, under the following circumstances:

—Where for compelling and scientifically sound methodological reasons its use is necessary to determine the efficacy or safety of a prophylactic, diagnostic or therapeutic method ; or

—Where a prophylactic, diagnostic or therapeutic method is being investigated for a minor condition and the patients who receive placebo will not be subject to any additional risk of serious or irreversible harm.”

What is troubling is that with the availability of other statistical methods, even imperfect ones, it is hard to see how withholding a proven therapy when those who receive the placebo are subject to an additional risk of serious harm is ever “necessary.”