Are Placebo-Controlled Studies Permissible?

Abstract

The word placebo comes from the ecclesiastical Latin, meaning “I shall please.”¹ It came to be used in medical practice as a term describing “all medicine prescribed more to please the patient than for its therapeutic effectiveness.”² In modern clinical research, placebos are inert substances, prepared so as to appear identical to the active substances being tested, which are provided to a control group in a randomized trial to give the control group an experience as similar as possible to that of the investigational group, except for the presence of the active ingredients being tested. In theory, any differences in response between the placebo control and investigational group (if the members of the two groups are assigned randomly and their identity is blinded both to the researchers and to the participants) is due to the active ingredients tested and not to a placebo effect or to chance.³