Background: Posttraumatic stress disorder (PTSD) may result from experiencing severe distress, and is in part amygdala dependent. Animal studies demonstrate that stress and negative affect enhance the amygdala-release of the neuropeptide substance P (SP) which binds to the neurokinin 1 (NK1) receptor. This positron emission tomography (PET) study investigated if NK1 receptor availability in the amygdala of PTSD patients were different from healthy control subjects. Methods: Eleven male patients with DSM-IV defined PTSD and nine healthy male control subjects were PET scanned during 60 min at rest using the NK1 preferring tracer [11C]GR205171. Parametric Patlak images were generated and analyzed using statistical parametric mapping software. The effect of age was co-varied out because the amount of NK1 receptors decline with age. Results: PTSD patients had elevated uptake of [11C]GR205171 in the amygdala as compared to controls, also when anxiety differences were controlled for. Conclusions: We suggest that enhanced NK1 receptor availability could be a risk factor for developing PTSD rather than reflecting trauma induced alterations.
Ämnesord
MEDICIN OCH HÄLSOVETENSKAP -- Klinisk medicin -- Psykiatri (hsv//swe)
MEDICAL AND HEALTH SCIENCES -- Clinical Medicine -- Psychiatry (hsv//eng)