Nocebo - Placebo

In its original application, nocebo had a very specific meaning in the medical domains of pharmacology, and nosology, and aetiology.

It was a subject-oriented adjective that was used to label the harmful, injurious, unpleasant or undesirable reactions (or responses) that a subject manifested - thus, nocebo reactions (or nocebo responses) - as a consequence of the administration of an inert, dummy drug, in cases where these responses had not been chemically generated, and were entirely due to the subject's pessimistic belief and expectation that the inert drug in question would produce harmful, injurious, unpleasant or undesirable consequences.

It is also important to remember that in these cases, despite the fact that there is no "real" drug involved, the actual harmful, injurious, unpleasant or undesirable biochemical, physiological, behavioural, emotional and/or cognitive consequences of the administration of the inert drug are very real.