The placebo effect has shifted from being a nuisance in clinical research to a promising model of an emerging neuroscience of mind–brain–body interactions. In fact, the interest in and the success of placebo research resides in its multifaceted meaning, which involves key issues in modern science – from neurobiology to philosophy, from ethics to social psychology, and from clinical trials design to medical practice. The first attempt to quantify the therapeutic effect of placebos was by Henry K Beecher in 1955, who published “The powerful placebo,” a paper reviewing 15 controlled trials involving 1802 patients. The term “placebo effect” is often used interchangeably with the term “placebo response.” However, the term “placebo effect” refers to any average improvement in the condition of a group of subjects that has received a placebo manipulation. To distinguish the pleasing from the noxious effects of placebo, several authors introduced and elaborated the term nocebo.