Trait Well-Being Predicts Placebo Response in Healthy Controls

• Activity Number: 187
• Type: Contributed
• Date/Time: Monday, August 2, 2010 : 10:30 AM to 12:20 PM
• Sponsor: ENAR
• Author(s): Hamdan Azhar*+ and Christian Stohler and Jon-Kar Zubieta
• Companies: University of Michigan and University of Maryland and University of Michigan
• Keywords: placebo effect ; neuroimaging ; psychology ; PLS regression

Abstract

The present study documents for the first time the relationship between general trait well-being and placebo response. Thirty-eight healthy young volunteers with no prior history of psychiatric illness or substance abuse completed personality questionnaires and underwent a 20-minute standardized pain challenge both in the absence and presence of a placebo with expected analgesic properties. Pain intensity was rated every 15 seconds on a scale of 0 to 100 and the percent difference in mean pain rating was defined as the primary outcome measure. Partial least squares regression (PLS) with leave-one-out cross-validation revealed a consistent effect of trait well-being in predicting placebo response. The overall variance explained by the model was nearly 30%, providing significant evidence of trait and state effects on placebo response.