BDNF and psychiatric disorder: Finally, altered BDNF/TrkB signaling has been implicated in the pathophysiology of neurodegenerative and psychiatric disorders including, AD, PD, HD, bipolar disease and epilepsy (Chen et al., 2008; Dmitrzak-Weglarz et al., 2008; Gupta et al., 2013; Liu et al., 2013; Plotkin et al., 2014; Chandley et al., 2015; Mariga et al., 2016; Nguyen et al., 2016).