Can an educational handout enhance placebo analgesia for experimentally-induced pain?

Abstract

The placebo effect is an interesting phenomenon whereby a dummy treatment can produce therapeutic benefit, such as, pain relief. While evidence for the placebo effect is growing, relatively few studies have explored ways of enhancing placebo effects. To address this, the current study tested whether placebo-induced analgesia could be enhanced by providing an educational handout about the efficacy of analgesics. Fifty university students were allocated to receive placebo treatment under the guise of a new analgesic formula, either with or without an educational handout, or to a no treatment control group before undergoing electrical and cold pressor pain tests. There was a placebo effect for electrically-induced pain with those receiving placebo treatment reporting significantly less pain compared with those who received no treatment. There was also some evidence of enhancement of this placebo-induced analgesia for electrically-induced pain as a result of the educational handout. No differences were found on cold pressor-induced pain. These findings suggest that providing educational information about a treatment could enhance its efficacy via the placebo effect. Future studies should test different methods of providing educational information in order to determine which elicit the strongest effects.

Figure 1. Mean (±SD) pain ratings pre- and posttreatment across groups for 60%, 80%, and 100% shock intensity in panel A, B, and C respectively.

Placebo treatment significantly reduced pain at 80% and 100% shock intensities. Further, the enhanced placebo group had significantly less pain at 80% shock intensity than the standard placebo group.