RESUMO
OBJECTIVE: The aim of this study was to determine whether absorption and spirituality predict the placebo response independently of expectancy. METHOD: This was an open study of self-treatment with self-selected Bach flower essences. Participants' expectancy of the effect of flower essences, attitudes to complementary medicine, holistic health beliefs, absorption, and spirituality were measured prior to treatment. One month after the start of treatment, participants responded to an e-mail enquiry about symptom change using a single seven-point change scale. RESULTS: One hundred sixteen participants (97 university undergraduates and 19 staff) completed all assessments. Spirituality and absorption together predicted additional variance compared with a cluster of expectancy measures comprising expectancy, attitude to complementary medicine, and holistic beliefs (increment in R(2)=.042, P=.032), and spirituality alone (but not absorption alone) predicted more additional variance than did the expectancy cluster (increment in R(2)=.043, P=.014). CONCLUSION: Our data are inconsistent with conventional explanations for the placebo effect. The mechanism underlying the placebo response is not fully understood.
