Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 64 (5), 537-41

Consistency of the Placebo Effect


Consistency of the Placebo Effect

Ben Whalley et al. J Psychosom Res.


Objective: The existence of reliable personality predictors of the placebo effect is controversial. For prediction to be possible, the response to placebo must be reliable. We tested the consistency of the placebo effect by assessing the response to four trials of placebo analgesic treatment.

Methods: Two identical experimental pain stimuli were administered simultaneously to matching fingers on both hands. Pain sensation was compared between one finger, which was treated with a placebo cream and the other which was not treated. Two placebo creams were used, each with a different label. The procedure was repeated between 1 and 8 days later using the same creams and order of presentation. Two personality traits (acquiescence and absorption) and response expectancy were assessed as potential predictors of the placebo effect.

Results: Placebo effects across trials were highly correlated (r=.60 and .77) when placebos bore the same name but were not significantly correlated when placebos had different names. Placebo effects were significantly associated with response expectancy but not with acquiescence or absorption.

Conclusions: Context-specific predictions of placebo response (e.g., expectancy) are possible, but personality predictors will not be consistent across contexts.

Similar articles

  • Placebo Analgesia Induced by Social Observational Learning
    L Colloca et al. Pain 144 (1-2), 28-34. PMID 19278785. - Randomized Controlled Trial
    Although it has long been known that psychosocial factors play a crucial role in placebo responses, no attempt has been made to understand if social observation shapes th …
  • Learning Potentiates Neurophysiological and Behavioral Placebo Analgesic Responses
    L Colloca et al. Pain 139 (2), 306-14. PMID 18538928. - Randomized Controlled Trial
    Expectation and conditioning are supposed to be the two main psychological mechanisms for inducing a placebo response. Here, we further investigate the effects of both ex …
  • How Prior Experience Shapes Placebo Analgesia
    L Colloca et al. Pain 124 (1-2), 126-33. PMID 16701952.
    Some studies indicate that placebo analgesia is stronger when pre-conditioning with effective analgesic treatments is performed, thereby suggesting that the placebo respo …
  • [Placebo Effect and Pain: Brain Bases]
    JM Ramos. Neurologia 22 (2), 99-105. PMID 17323235. - Review
    In placebo analgesia at least two anatomically differentiated cerebral systems work together. The guiding mechanism, which appears to be located prefrontally, is activate …
  • Placebo Analgesia: Cognitive Influences on Therapeutic Outcome
    A Watson et al. Arthritis Res Ther 14 (2), 206. PMID 22494482. - Review
    The therapeutic response to a drug treatment is a mixture of direct pharmacological action and placebo effect. Therefore, harnessing the positive aspects of the placebo e …
See all similar articles

Cited by 19 PubMed Central articles

See all "Cited by" articles

LinkOut - more resources