Nonspecific Factors in Drug Effects: Placebo Personality

The importance of the concept of placebo in medicine and psychology historically and in practice was noted, including attitudes and ethical concerns. This paper reviewed evidence relating to personality correlates of responsivity to placebos. It was concluded that a trait model of responsivity to placebos was largely unsubstantiated and suggested that other nonspecific factors of drug effects may be more influential in reactions to placebos. Evaluation of measures of response to placebos and methodological issues is needed. Potential neurochemical substrates for action of placebos were suggested as promising.