BDNF and psychiatric disorder: This is a significant question, since cognitive ability and synaptic plasticity are influenced by the levels of BDNF (Lu et al., 2013; Park and Poo, 2013; Vaynman et al., 2004) and BDNF signaling is reduced in many neurodegenerative and psychiatric diseases (Autry and Monteggia, 2012; Zuccato and Cattaneo, 2009).