Znieczulajacy kontekst: Wplyw placebo na doswiadczanie bolu - aspekt psychologiczny [Analgesic context: The influence of placebo on experiencing pain]

Placebo effects have been extensively investigated in recent years and a number of conceptual frameworks have been developed to capture their mechanisms. The aim of the article is to summarize and critically discuss the current state of the art of placebo effects in pain research and clinical practice. Conceptualization of a placebo is proposed and main placebo effects, i.e., placebo effect and nocebo effect, are described. The effectiveness of the placebo in pain research and clinical practice is evaluated. Main methods of the induction of placebo effects are presented, i.e., classical conditioning, verbal suggestions and observational learning. Psychological mechanisms of placebo effects are discussed, including expectancy and classical conditioning, as well as emotional factors contributing to the placebo effects, i.e., anxiety, fear and stress. Last but not least, ethical issues in the placebo use in research and clinical practice are considered. The article is part of a research project no. 2014/14/E/HS6/00415 funded by the National Science Centre, Poland.