Expectancy Effect in Three Mind-Body Clinical Trials.
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.
National College of Natural Medicine, Portland, OR, USA matthewhicks12@gmail.com.
Matthew
M
Hicks
National College of Natural Medicine, Portland, OR, USA.
Douglas
D
Hanes
National College of Natural Medicine, Portland, OR, USA Oregon Health & Science University, Portland, OR, USA.
Helané
H
Wahbeh
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D019122:Meditation; D008875:Middle Aged; D026441:Mind-Body Therapies; D064866:Mindfulness; D013315:Stress, Psychological / Q000628:therapy*; D011795:Surveys and Questionnaires
expectancy; meditation; mind-body; mindfulness-based stress reduction