‘External timing’ of placebo analgesia in an experimental model of sustained pain

Background Research on placebo analgesia commonly focuses the impact of information about direction (i.e., increase or decrease pain) and magnitude expected analgesic effect, whereas temporal aspects expectations have received little attention so far. In a recent study, using short-lasting, low-intensity stimuli, we demonstrated that onset is influenced by information. Here, investigate whether same effect suggestions can be found in longer lasting, high-intensity pain Cold Pressor Test (CPT). Methods Fifty-three healthy volunteers were allocated to one three groups. Participants informed application an (inert-)cream would reduce after 5 min (P5) 30 (P30). The third group was cream only had hydrating properties (NE). All participants completed CPT at baseline 10 (Test 10) 35 35) following application. Percentage change exposure time (pain tolerance) from (?10) (?35) changes heart rate (HR) during compared between Results ?10 greater P5 than NE P30, indicating present expecting early analgesia. ?35 P30 NE, reflecting delayed maintained P5. HR differences groups not significant. Conclusions Our data suggest ‘externally timing’ may possible for prolonged types pain. Significance effects mainly influence strong weak) but ignores expectations. our study volunteers, reported followed provided. Such ‘external could aid clinical use treatment (e.g., open-label placebos) also support efficacy active drugs.