BDNF and depressive disorder: Serum BDNF is reduced under conditions of acute/chronic stress, including chronic alcoholic intake and chronic inflammation, and is associated with alcohol withdrawal severity and depression alcoholic patients (Hensler, Ladenheim and Lyons, 2003; Hilburn et al., 2011; Huang et al., 2008, 2011; John MacLennan, Leea and Walker, 1995; Shi et al., 2010; Xu et al., 2010).