Expectancy Effect in Three Mind-Body Clinical Trials

J Evid Based Complementary Altern Med. 2016 Oct;21(4):NP103-9. doi: 10.1177/2156587216652572. Epub 2016 Jun 5.


Expectancy, arguably the prime component of the placebo effect, has been shown to significantly modify the effects of many treatments. Furthermore, various forms of mind-body interventions have demonstrated effective improvements in outcomes. The aim of this study was to examine the relationship between pretreatment expectations and symptom reduction in a secondary analysis of 3 mind-body intervention programs. An adjusted correlation and regression analysis compared data from a 6-question expectancy questionnaire to a self-reported clinical impression of change score. Only 1 of the 6 expectancy questions in 1 of the 3 studies reached significance (B = 0.087; P = .025). The combined data from all 3 studies did not reveal significant expectancy effects. The positive effects of mindfulness meditation appear to be independent of an expectancy effect.

Keywords: expectancy; meditation; mind-body; mindfulness-based stress reduction.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Female
  • Health Knowledge, Attitudes, Practice*
  • Humans
  • Male
  • Meditation
  • Middle Aged
  • Mind-Body Therapies*
  • Mindfulness*
  • Stress, Psychological / therapy*
  • Surveys and Questionnaires