Plasma Neuropeptide Y Concentrations in Combat Exposed Veterans: Relationship to Trauma Exposure, Recovery from PTSD, and Coping

Background There is emerging interest in examining the role of plasma neuropeptide Y (NPY) as a protective stress factor. Methods To further investigate this possibility, plasma NPY was measured in 11 nonexposed veterans, 11 combat-exposed veterans without posttraumatic stress disorder (PTSD), and 12 veterans with current PTSD. Results A significant group difference in plasma NPY (F2,31 = 5.16, p = .012) was observed, reflecting higher NPY levels in exposed veterans without PTSD than in nonexposed but comparable levels in veterans with current PTSD. Among those without current PTSD, veterans with past PTSD had higher NPY levels than those without past PTSD (t9 = 2.71, p = .024). After controlling for all other variables, NPY levels were significantly predicted by extent of symptom improvement and lower combat exposure and significant at a trend level with positive coping. Conclusions Plasma NPY levels may represent a biologic correlate of resilience to or recovery from the adverse effects of stress.