[About placebos and nocebos: healing through words].
The concept of "the placebo effect", mainly applied to the therapeutic management of pain, has been extensively studied and refers to the possibility to obtain analgesic effects through the administration of inert substances. The opposite evidence, i.e. the induction of pain through verbal suggestions, has validated the concept of nocebo effect, that implies that the expectative of a negative event could cause, per se, the worsening of a symptom. The neurochemical approach of the placebo-nocebo phenomenon involves the existence of opposite neuronal systems, activated for expectations regarding pain. Opioids would mediate placebo analgesia whereas cholecystokinin would account for the increase in pain. Healing through words, under the light of the present knowledge, would imply that a link exists between psychosocial and pharmacologic effects, important from the point of view of the therapeutic management of pain.
Adler
Edda
E
Instituto de Investigaciones Farmacológicas, Consejo Nacional de Investigaciones Científicas y Tecnológicas. eadler@ffyb.uba.ar
D006801:Humans; D010146:Pain / Q000209:etiology*; D015990:Placebo Effect