We define the meaning response as the physiologic or psychological effects of meaning in the origins or treatment of illness; meaning responses elicited after the use of inert or sham treatment can be called the “placebo effect” when they are desirable and the “nocebo effect” when they are undesirable…
Insofar as medicine is meaningful, it can affect patients, and it can affect the outcome of treatment. Most elements of medicine are meaningful, even if practitioners do not intend them to be so. The physician’s costume (the white coat with stethoscope hanging out of the pocket), manner (enthusiastic or not), style (therapeutic or experimental), and language are all meaningful and can be shown to affect the outcome; indeed, we argue that both diagnosis and prognosis can be important forms of treatment.
— Daniel E. Moerman and Wayne B. Jonas, Deconstructing the Placebo Effect and Finding the Meaning Response, The Placebo: A Reader