What are the Best Placebo Interventions for the Treatment of Pain?

More invasive and impressive therapeutic rituals are generally believed to be more powerful interventions than less impressive ones. This chapter reviews and discusses evidence from randomized clinical trials and meta-analyses for such a differential effectiveness of placebo interventions. Evidence from clinical research that different types of placebo are regularly associated with different magnitudes of placebo effect is limited. However, one area where hints from a variety of sources are accumulating is sham acupuncture in the treatment of pain. Furthermore, there is preliminary evidence that sham surgery and ambiguous evidence that sham injections are associated with enhanced placebo effects on pain. Among the factors that may account for a greater effectiveness of such treatment procedures are the lively perceptual context of the procedures themselves, the attention and enhanced emotional support by healthcare providers, and the increased expectation and motivation of patients. A differential effectiveness of placebo control procedures in clinical trials would have important implications for clinical research.