Corticotropin-releasing hormone anxiogenic effect

The neuropeptide Y (NPY) and gamma-amino-butyric acid (GABA) may be associated with resilience to the development of PTSD. A depletion of plasma NPY and a blunted NPY response to yohimbine was reported in soldiers with PTSD when compared to nontraumatized control subjects (Rasmusson et al., 2000). NPY counters the anxiogenic effect of corticotropin-releasing hormone (CRH) and counters effects of norepinephrine in brain regions associated with fear and anxiety (reviewed in Yehuda, 2006). Recently, Vaiva et al. (2006) reported that road traffic accident victims with low levels of GABA were more likely to develop PTSD. Elevated levels of GABA 1 year posttrauma were associated with trauma recovery. 

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