THE ROLE of the placebo in the practice of medicine is a significant one and worthy of more attention than it usually receives. For purposes of this discussion, we may use Shapiro's1 definition of placebo: A placebo is defined as any therapeutic procedure (or that component of a therapeutic procedure) which is given deliberately to have an effect, or which unknowingly has an effect on a patient, symptom, disease, or syndrome, but which is objectively without specific activity for the condition being treated. The placebo is also used to describe an adequate control in experimental studies. A placebo effect is defined as the changes produced by placebos. The true importance of the placebo emerges as one reviews the history of medical treatment. No treatment of any specific value is found in the pages of Hippocrates and this remains true for over a thousand years according