Placebo analgesia: Friend or foe?

Abstract

The magnitude of placebo analgesia is influenced by environmental and perceptual factors. Environmental factors include past exposure to effective analgesic agents and verbal suggestions and cues that foster a perception of being given an effective treatment. Environmental factors, in turn, influence the proximate psychologic mediators of placebo analgesia, which include decreased desire for and increased expectations of pain relief. Strategies to maximize placebo analgesic effects in clinical practice could focus on using verbal suggestions and external cues to increase expectations of pain relief and/or decrease the perceived need for pain reduction. Placebo analgesic effects could be minimized in clinical trials by avoiding these same suggestions and cues.

Hypnobo: Perspectives on Hypnosis and Placebo

“…Pain, however, may not be the best domain to explore hypnosis as placebo -psychopathology, for example, may be far superior (Raz, 2006) -and the effect of suggestion, hypnotic and nonhypnotic, has been a major force in extending the notion of placebo to such parameters as anticipation and expectation (Spanos, Perlini, & Robertson, 1989). [Compare with recent independent and multidisciplinary accounts on this topic (Green, 2006;Price, 2006;Price, Fillingim, & Robinson, 2006;Sharav & Tal, 2006;Sharav & Tal, 2007)]. In this regard, hypnotizability may be of Raz placebo value by generating positive expectancies (Van Dyck & Hoogduin, 1990).…”

Placebo Analgesia Enhances Descending Pain-Related Effective Connectivity: A Dynamic Causal Modeling Study of Endogenous Pain Modulation

“…One way to mitigate this problem is through the enhancement of currently available treatments. Placebo analgesia (PA) is an endogenous process that can effectively reduce an individual’s pain 31 . Furthermore, PA is seen as an acceptable treatment by many patients who have learned that they have received a placebo 7 .…”

“…This complexity is reflected in the results of neuroimaging studies of PA, which have shown effects at regional and network levels. Multiple studies have associated PA with reductions in BOLD activity in pain-related brain areas such as the thalamus, somatosensory cortices, insula, and anterior cingulate cortex 14, 31, 42 . Increased activity in regions responsible for cognitive control and evaluative processes, such as the dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), and rostral anterior cingulate cortex (rACC), has also been observed in anticipation of and during PA 14, 31, 42 .…”

“…Multiple studies have associated PA with reductions in BOLD activity in pain-related brain areas such as the thalamus, somatosensory cortices, insula, and anterior cingulate cortex 14, 31, 42 . Increased activity in regions responsible for cognitive control and evaluative processes, such as the dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), and rostral anterior cingulate cortex (rACC), has also been observed in anticipation of and during PA 14, 31, 42 . Afferent inhibition and the activation of pathways involving the release endogenous opioids, noradrenaline and serotonin 4, 6, 29, 33 have been implicated in these activation differences.…”

Effective connectivity predicts future placebo analgesic response: A dynamic causal modeling study of pain processing in healthy controls

“…Specifically, additional clarification of the cortico-cortical interactions involved in placebo analgesia may aid in meeting this need (Wiech, Ploner, & Tracey, 2008). Given the variability observed in placebo response across studies (Price, Fillingim, & Robinson, 2006; Price, Finniss, & Benedetti, 2008), neural factors predicting individual differences in placebo analgesic response could likely aid in treatment decision and personalization of treatment to aid in the optimization of pain interventions.…”