Characterized by chronic arousal, re-experience of the event, and avoidance of stimuli related to the event is the anxiety disorder called post-traumatic stress disorder (PTSD) that may occur in individuals exposed to a traumatic event.

Due to altered pain processing in the brain, PTSD patients have reduced pain sensitivity; reports a study in the January issue of the Archives of General Psychiatry (one of the JAMA/Archives journals).

The study, led by Elbert Geuze, Ph.D., of Central Military Hospital and the Rudolph Magnus Institute of Neuroscience (Utrecht, the Netherlands) conducted a study to examine neural correlation of pain processing in PTSD patients which consisted of psychophysical assessment and neuroimaging with functional magnetic resonance imaging (fMRI)--the use of magnetic resonance imaging to learn which regions of the brain are active in a specific function.

"Before fMRI, patients with PTSD already showed a significant reduction in pain sensitivity. During imaging, patients with PTSD rated a fixed temperature as significantly less painful than control veterans.

Patients with PTSD showed altered pain processing in brain areas associated with mood and cognitive pain processing.

"These data provide evidence for reduced pain sensitivity in PTSD. The witnessed neural activation pattern is proposed to be related to altered pain processing in patients with PTSD."

Find more details in this report.