Low cerebrospinal fluid neuropeptide Y concentrations in posttraumatic stress disorder

Abstract

Background: 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.

Methods: 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).

Results: 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).

Conclusions: 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.

Figure 1

Cerebrospinal fluid concentrations of neuropeptide Y in posttraumatic stress disorder (PTSD) patients and healthy comparison subjects. *p < .0008 versus healthy subjects.