Cand.philol. Espen Bjørkedal disputerer for ph.d.-graden i psykologi og vil offentlig forsvare avhandlingen:
“Active Placebo - The relation of treatment expectancies to active analgesic treatments”
Kort sammendrag av avhandlingen:
The placebo effect can be measured both as the difference between a group receiving placebo and a no treatment control group, or as the difference between a group receiving a drug with positive treatment expectancies and a group receiving a drug with no expectancies. If there is a difference in the size of the placebo effect in these two situations, then it suggests that drugs and placebos interact. This has serious implications for the design and interpretation of placebo controlled clinical trials. We investigated this possibility in one experiment by giving both caffeine and placebo with positive treatment expectancies and without expectancies to healthy subjects after the induction of pain. The results indicated that the placebo effect was larger when caffeine was given compared to when placebo was given.
In two other experiments on healthy subjects we investigated the effect of active treatments for pain when they were either expecting reduced pain, increased pain, or had no expectations. The results showed that a topical anaesthetic cream was effective in reducing pain, but that this effect was reversed when subjects expected the cream to increase pain. This suggests that negative treatment expectancies can have a strong impact on the effects of active treatments for pain. The present work is relevant for both the design and interpretation of clinical trials and for clinical practice. Clinical trials assume that the only difference between drugs and placebos are the pharmacological action of the drug. However, if placebo responses are larger in the presence of the active drug the assumption might not always hold. The modulation of treatment effects by treatment expectancies points to the importance of doctor-patient communication in the therapeutic context.
(Avhandlingen er tilgjengelig for utlån hos Seksjon for forskningstjenester frem til disputasdato)
Veileder
Hovedveileder professor Magne Arve Flaten, NTNU
Bedømmelseskomiteen
Professor Paul Enck, University of Tübingen, Germany, 1. opponent
Dr.Med. Karin Meissner, Ludwig-Maximilian University of Munich, Germany, 2. opponent
Førsteamanuensis Susanne Wiking, Institutt for psykologi, Det helsevitenskapelige fakultet, UiT – Norges arktiske universitet – leder av komité
Disputasleder
Professor Joar Vittersø, Institutt for psykologi, Det helsevitenskapelige fakultet, Universitetet i Tromsø – Norges arktiske universitet
Prøveforelesning over oppgitt emne holdes kl. 10.15, samme sted: "Placebo effects beyond pain and placebo analgesia”