The Pharmaceutical Journal
Vol 275 No 7365 p274
3 September 2005

This article
Reprint   Photocopy

  Acrobat Reader

News summary

Placebo activates brain pain response

Administration of a placebo with implied analgesic properties activates brain areas involved in suppressing pain, a study has found (Journal of Neuroscience 2005;25:7754).

Researchers used a saline solution to induce pain in volunteers, who were then given a placebo which they were told was thought to have analgesic properties. Using molecular imaging techniques, the researchers examined the activity of the endogenous opioid system on µ-opioid receptors.

Significant placebo-induced activation occurred in a number of brain regions. These activations were paralleled by lower ratings of pain intensity. “These data demonstrate that cognitive factors are capable of modulating physical and emotional states through site-specific activation of µ-opioid receptor signalling in the human brain,” the authors conclude.