Pain and the Placebo/Nocebo Effect

In the last 20 years, placebo and nocebo research has provided scientific ground for a phenomenon once believed to be only patient mystification, or at best a variable to control in clinical trials. Neurochemical, pharmacological and neuroimaging studies are elucidating the mechanisms by which the activation of identifiable neural pathways produces symptom changes following treatments devoid of specific activity. Placebo analgesia and nocebo hyperalgesia are among the best studied models, and awareness of the possible clinical application of research knowledge can lead to the optimization of the context surrounding the patient, in order to maximize the placebo component and minimize the nocebo component present in any treatment.