Low cerebrospinal fluid neuropeptide Y concentrations in posttraumatic stress disorder

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. 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).

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.