In medicine, a Nocebo Reaction or response refers to harmful, unpleasant, or undesirable effects a subject manifests after receiving an harmless drug or placebo. While the placebo effect refers to health benefits produced by a treatment that should have no effect, Nocebo responses are caused only by the subject’s negative belief and expectation that the drug will produce negative consequences.
The term “nocebo response” was coined in 1961 by Walter Kennedy and is based on the Latin word nocebo (“I shall harm”) which is the opposite of the Latin word placebo (“I shall please”). S
Some attribute nocebo responses (or placebo responses) to a subject’s personality (eg. prone to depression or anxiety), however there is no evidence that a patient who has a nocebo/placebo response to one treatment will manifest a nocebo/placebo response to a different treatment. There is no proven nocebo/placebo-responding trait or propensity.