NPY and major depressive disorder: Besides, the monoamine hypothesis proposes that the serotonin (5-HT), norepinephrine (NE), dopamine (DA), and neuropeptide Y (NPY) pathways play a crucial role in the pathophysiology of depression and anxiety (Eaton et al., 2007; Mickey et al., 2011; Hamon and Blier, 2013) and may aggravate depression and anxiety (Brigitta, 2002; Aan Het Rot et al., 2009) and sensorimotor deficits (Geyer et al., 2001; Wurm et al., 2007).