title: [Placebo effects and controlled clinical trials].
abstract: Placebo effects have been recognized for a long time, but the underlying mechanisms are unknown. The analgesic effect of placebo has been studied, and one hypothesis is that placebo-induced analgesia is mediated by endorphins. The opiate antagonist naloxone has been used in an attempt to prevent this analgesia. Partial antagonism has been shown, but the placebo still has a considerable analgesic effect. This means that release of endorphins cannot be the only explanation of the analgesia. Patients participating in clinical trials to compare an active drug with a placebo are informed that they may receive the latter. This information leads to a reduction of the effect of the active drug. Possibly the participating patients should not be given this information.
authors.affiliation: Institutt for informatikk, Universitetet i Oslo.
authors.forename: E
authors.initials: E
authors.lastname: Skovlund
mesh_terms: D000700:Analgesics / Q000008:administration & dosage; D000818:Animals; D004723:Endorphins / Q000502:physiology; D004992:Ethics, Medical; D006801:Humans; D009270:Naloxone / Q000008:administration & dosage; D009619:Nociceptors / Q000187:drug effects / Q000502:physiology; D009664:Norway; D010146:Pain / Q000188:drug therapy / Q000523:psychology; D015990:Placebo Effect; D016032:Randomized Controlled Trials as Topic
chemical_list: D000700:Analgesics; D004723:Endorphins; D009270:Naloxone
vernacular_title: Placeboeffekter og kontrollerte kliniske forsøk.