A survey of physicians in 1979 found that some doctors give a placebo to patients who complain of pain for which the physician can find no cause. If the patients' pain improves, these doctors conclude that it had no physical basis. The medical researchers who conducted the survey claimed that these doctors do not understand the placebo effect. Why?

Answer 1

In the patient's mind, the placebo reduces anxiety (and therefore some of the stress). This reduction can decrease the perceived pain.

http://drdavespsychologypage.homestead.com/Placebo_Power.pdf

http://drdavespsychologypage.homestead.com/Placebo_Power_Doubled.pdf