Effects of anxiety and morphine on the anticipation and perception of painful radiant thermal stimuli.

Abstract

Using human subjects with a history of opiate addiction, the response to painful stimulation under conditions of anxiety-arousing formality and reassuring informality in subjects given subcutaneous morphine and in control subjects receiving no medication was measured. It was found that morphine is most effective in raising the differential threshold to pain stimulation when the subject is anxious, but that under reassuring conditions morphine has no significant effect. Similar findings were found for anticipatory responses to pain. "There is some indication in this experiment that reduction of anxiety can be as effective as morphine in the relief of thermal pain and that morphine is only effective as an analgesic agent when anxiety is present." (PsycINFO Database Record (c) 2006 APA, all rights reserved)