Pain and placebo analgesia: two sides of the same coin

Abstract

Health professionals have traditionally taken a negative view of the placebo phenomenon. This paper highlights current theories, biological and psychological mechanisms that explain why placebo analgesia should now be considered as an asset, rather than a hindrance, to pain management and patient care. First, an historical perspective outlines medical scepticism towards placebo and the improved understanding of central and descending mechanisms of pain control that have changed that view. Next, the key psychological mechanisms of conditioning, expectancy and desire for pain relief are discussed, in conjunction with the cortical mechanisms of action which account for placebo analgesia. Nocebo hyperalgesia (the antithesis of placebo analgesia) is summarised. The discussion uses the evidence to propose three main considerations for clinical application: (i) biomedical explanations about pain are potentially detrimental to patients in pain; (ii) consumatory beliefs, actions and behaviours mediate both self-efficacy and placebo analgesia and should be optimised during rehabilitation; and (iii) therapist's communication can reduce or heighten their patient's pain.