BDNF and major depressive disorder: Schizophrenia and MDD also inhibit other important neuroplastic mechanisms such as synaptic plasticity (Law and Deakin, 2001; Kolomeets et al., 2007; Kobayashi, 2009; McEwen et al., 2012; Sanderson et al., 2012) and BDNF expression (Krishnan and Nestler, 2008; Green et al., 2011; Favalli et al., 2012) within the hippocampus.