Placebo analgesic effects appear to be related to patients' perception of the therapeutic intervention. In this paper, we review quantitative findings of how the relationship with the physician and the verbal suggestions given for relief may influence patients' perception of a treatment and how patients' expectations and emotional feelings may affect treatment outcome. We also present qualitative data from interviews with patients who have experienced pain relief following a placebo or an active treatment. A special focus is given to the temporal development of placebo analgesia at psychological and neurophysiological levels. Finally, we discuss the extent to which the quantitative and qualitative findings supplement or contrast with each other, and we touch upon possible implications of patients' direct experience as central for placebo analgesia.
Philos Trans R Soc Lond B Biol Sci. 2011 Jun 27;366(1572):1913-21. Vase L, Nørskov KN, Petersen GL, Price DD. Department of Psychology, Aarhus University, , Jens Christian Skous Vej 4, 8000 Aarhus C, Denmark.