Is the rationale more important than deception? A randomized controlled trial of open-label placebo analgesia.
Locher C, Frey Nascimento A, Kirsch I, Kossowsky J, Meyer A, Gaab J.
Pain. 2017 Dec;158(12):2320 2328.
Healthy volunteers were recruited to an experimental heat pain analgesia randomized controlled trial. Forty healthy volunteers in each group were randomly assigned to deceptive placebos, no treatment, open-label placebo without rationale, or open-label placebo with rationale (explaining that placebo is powerful and effective for pain). An inert white placebo cream was used once and heat pain measurements (subjective intensity, unpleasantness and objective heat tolerance) were obtained before and after placebo cream treatment. There was no significant difference in any of the groups in objective heat pain tolerance after treatment (P=0.724). However, the 2 groups with a rationale (open-label placebo with rationale and deceptive placebos) reported significantly lower heat pain intensity (P=0.033) and unpleasantness (P=0.016) ratings compared to the open-label placebo without rationale group. There was no significant difference (P=0.272) in the subjective heat pain ratings in the open-label placebo with
rationale and deceptive placebos groups. The authors conclude that in healthy volunteers a satisfactory explanation of the placebo analgesia is effective and questions whether the cover-up of placebo in research is necessary.
Composed by Elaine Boland.