Format

Send to

Choose Destination
See comment in PubMed Commons below
Eur J Pain. 2016 Oct 17. doi: 10.1002/ejp.961. [Epub ahead of print]

Effects of subtle cognitive manipulations on placebo analgesia - An implicit priming study.

Author information

  • 1Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden.
  • 2Program in Placebo Studies and Therapeutic Encounters, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA.
  • 3Department of Clinical Neuroscience, Osher Center for Integrative Medicine, Karolinska Institutet, Stockholm, Sweden. karin.jensen@ki.se.
  • 4Program in Placebo Studies and Therapeutic Encounters, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA. karin.jensen@ki.se.

Abstract

BACKGROUND:

Expectancy is widely accepted as a key contributor to placebo effects. However, it is not known whether non-conscious expectancies achieved through semantic priming may contribute to placebo analgesia. In this study, we investigated if an implicit priming procedure, where participants were unaware of the intended priming influence, affected placebo analgesia.

METHODS:

In a double-blind experiment, healthy participants (n = 36) were randomized to different implicit priming types; one aimed at increasing positive expectations and one neutral control condition. First, pain calibration (thermal) and a credibility demonstration of the placebo analgesic device were performed. In a second step, an independent experimenter administered the priming task; Scrambled Sentence Test. Then, pain sensitivity was assessed while telling participants that the analgesic device was either turned on (placebo) or turned off (baseline). Pain responses were recorded on a 0-100 Numeric Response Scale.

RESULTS:

Overall, there was a significant placebo effect (p < 0.001), however, the priming conditions (positive/neutral) did not lead to differences in placebo outcome. Prior experience of pain relief (during initial pain testing) correlated significantly with placebo analgesia (p < 0.001) and explained 34% of placebo variance. Trait neuroticism correlated positively with placebo analgesia (p < 0.05) and explained 21% of placebo variance.

CONCLUSIONS:

Priming is one of many ways to influence behaviour, and non-conscious activation of positive expectations could theoretically affect placebo analgesia. Yet, we found no SST priming effect on placebo analgesia. Instead, our data point to the significance of prior experience of pain relief, trait neuroticism and social interaction with the treating clinician.

SIGNIFICANCE:

Our findings challenge the role of semantic priming as a behavioural modifier that may shape expectations of pain relief, and affect placebo analgesia.

PMID:
27748563
DOI:
10.1002/ejp.961
[PubMed - as supplied by publisher]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley
    Loading ...
    Support Center