"Neuropeptide Y (NPY), a peptide neurotransmitter that regulates stress and anxiety, has been proposed to be a stress resilience factor in humans. Posttraumatic stress disorder (PTSD) is a stress-related anxiety disorder," investigators in the United States report (see also Post-Traumatic Stress Disorders).

"We hypothesized that central nervous system NPY is dysregulated in PTSD and sought to redress the absence of central NPY data in the disorder. We determined morning NPY concentrations in cerebrospinal fluid (CSF) from 10 male subjects with chronic combat-related PTSD and from 13 healthy men. Neuropeptide Y-like immunoreactivity was measured by enzyme immunoassay (EIA). As compared with the normal comparison subjects, PTSD patients had significantly lower concentrations of CSF neuropeptide Y (mean CSF NPY was 360.0 +/- 17.7 pg/mL in control subjects but only 233.6 +/- 28.7 pg/mL in PTSD patients [p = .0008]). Adjustments for age and body mass index (BMI) still revealed a highly significant reduction in CSF NPY in the PTSD group (p = .003)," wrote R. Sah and colleagues, University of Cincinnati, Medical Department.

The researchers concluded: "Men with combat-related PTSD have low CSF concentrations of the putative resiliency hormone NPY, possibly related to the disorder or to extreme stress exposure per se."

Sah and colleagues published their study in Biological Psychiatry (Low Cerebrospinal Fluid Neuropeptide Y Concentrations in Posttraumatic Stress Disorder. Biological Psychiatry, 2009;66(7):705-707).

For additional information, contact R. Sah, University of Cincinnati, College Medical, Dept. of Psychiatry, Genome Research Institute A133, 2170 E Galbraith Rd., Cincinnati, OH 45237, USA.

The publisher of the journal Biological Psychiatry can be contacted at: Elsevier Science Inc., 360 Park Avenue South, New York, NY 10010-1710, USA.