Expectations, conditioning, and the placebo effect do not differ between fibromyalgia patients and healthy controls but might be differently associated

While the classical placebo theorem is supported in healthy controls, with conditioning influencing expectations, which in turn predict the placebo effect, these associations are not observed in fibromyalgia, where prior clinical experience plays a more significant role. These findings underscore the impact of previous negative clinical experiences on the placebo effect and, possibly, on responses to effective treatments.