Placebo Response

I. Introduction During this century the number of potent pharmaceutical compounds available to the doctor has been rapidly increasing. In psychiatry the last five years alone has seen the introduction of several powerful drugs classified as "tranquilizers," each of which is a distinct advance on any previous compound. This situation has led to the need to develop accurate clinical trials, with statistical assessment of the results. These clinical trials have usually involved the use of a dummy, or placebo, similar to the drug under investigation. In theory any response obtained with patients taking the active principle but not in the patients taking the placebo should be due to the drug. In practice a number of interesting and unexpected results have been obtained. Thus, Wolf and Pinsky4(1954), comparing the effects of mephenesin and a placebo, found similar improvement with both, and even side-reactions occurred with the inert tablet. Hawkings