| Reference code: | PT/FB/BL-2006-161.18 |
| Location: | Arquivo PCA - Pasta 12/2006
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Title:
| Is there a placebo responder?
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| Publication year: | 2008
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URL:
| http://www.abstractsonline.com/viewer/viewAbstractPrintFriendly.asp?CKey={B3B9FDB9-2CE9-4F65-968D-B9668D1589B2}&SKey={140A3D71-1A65-43A4-BA8D-1D19B9481117}&MKey={C9574065-70A7-4248-B115-6786733F7556}&AKey={51FD9D5C-B558-4333-95E6-175995909423}
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| Abstract/Results: | ABSTRACT:
AIM OF INVESTIGATION:
Both verbally induced expectation and conditioning procedures have been reported as important underlying psychological mechanisms of placebo analgesia. There is great variability in this analgesic response, suggesting a role for individual differences. The present study investigated the relation of personality factors to placebo analgsia. Placebo analgesic responses were classically conditioned by pairing administration of placebo capsules with surreptitious lowering of pain intensity in one group. In one control group, placebo capsules were administrated while pain intensity was kept unchanged. In a second control group, placebo capsules were not administrated while pain intensity was lowered.
METHODS:
69 subjects (38 females) participated in the study. The subjects were randomly assigned to three groups where cold pain was induced by a thermode attached to the right volar forearm. Cold pain was delivered four times, each exposure lasting for 2 minutes. In the conditioned group temperatures increased from -100C to 00C to +50C across the three first pain exposures after the administration of placebo capsules. A conditioned stimulus (CS) control group also received the capsules but the temperatures were kept constant (-100C) after the administration of the capsules. An unconditioned (US) control group received the same temperatures as the conditioned group but did not receive the capsules. The placebo analgesic response was assessed by adding a fourth cold pain induction at -100C at the end of the experiments in all three groups. We hypothesized that placebo analgesic responding would occur in the conditioned group but not in the other two. The Cattell 16PF and the Fear of Pain Questionnaire were administered prior to the experimental procedures. Placebo analgesia was defined as a reduction in pain from the first to the last pain induction.
RESULTS:
Placebo analgesia was observed in the conditioned group, and somewhat surprisingly also in the CS control group, compared to the US control group. No personality factors predicted the placebo analgesic response. The anxiety factor on the 16PF inventory positively predicted cortisol levels (ß = .26, t = 2.2, p = .031). Fear of pain positively predicted pain intensity (ß = .2, t = 2.51, p = .014), pain unpleasantness (ß = .25, t = 2.16, p = .034), and stress scores (ß = .27, t = 2.3, p = .024).
CONCLUSIONS:
A placebo responder subtype could not be identified in the personality tests used in the present study. This supports the idea that variability in placebo responses are not due to personality traits, but are due to past experiences and situational factors.
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| Accessibility: | Document does not exist in file
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Language:
| eng
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Author:
| Lyby, P.
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Secondary author(s):
| Bjørkedal, E., Aslaksen, P., Flaten, M.
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Document type:
| Online abstract
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Number of reproductions:
| 1
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Reference:
| Lyby, P., Bjørkedal, E., Aslaksen, P., & Flaten, M. (2008). Is there a placebo responder? Poster presented at the 12th World Congress on Pain, Glasgow, UK. Abstract retireved from http://www.abstractsonline.com/viewer/?mkey=%7BC9574065%2D70A7%2D4248%2DB115%2D6786733F7556%7D
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| Indexed document: | No
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| Keywords: | Placebo analgesia / Classical conditioning / Fear of pain / Personality / Stress
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