Considerable evidence indicates that in the CNS neuropeptide Y (NPY) can attenuate the response to stress, and has therapeutic potential for PTSD as well as for depression (reviewed in Heilig, 2004; Morales-Medina et al., 2010; Wu et al., 2011; Sah and Geracioti, 2013; Enman et al., 2015; Reichmann and Holzer, 2016; Sabban et al., 2016; Schmeltzer et al., 2016). This evidence concerns the gene NPY and major depressive disorder.