A comparison of open-label and deceptive placebo analgesia in a healthy sample

A small number of studies have supported the efficacy of open-label placebos (OLPs) in reducing pain. However, research comparing the effectiveness of OLPs with deceptive placebos (DPs) is limited, and the relative impact on pain tolerance versus intensity are not yet understood. This study therefore, examined the effectiveness of a nasal placebo administered openly and deceptively on pain intensity and tolerance during a cold pressor test (CPT).

75 healthy participants were allocated to one of three groups; OLP (n = 25), DP (n = 26) and no-treatment (NT; n = 24). A pre-test post-test design was used, with all participants completing a baseline and post-treatment CPT, following placebo administration in the treatment groups.

A one-way ANCOVA revealed significant differences between groups for pain intensity, with planned contrasts revealing that this effect was driven by an increase in pain intensity scores for the NT group within the post treatment CPT, which was not evident in the OLP and DP groups. There were no significant differences between groups for changes in pain tolerance.

The increase in pain intensity reported within the post-treatment CPT in the NT group was not apparent in either the OLP or DP groups, with no significant differences between OLP and DP effectiveness. These findings suggest that deception may not be necessary for effective placebo treatment and have implications for the management of pain.