BDNF and Mental deterioration: Increased BDNF serum levels are associated with reduced cognitive decline (Laske et al., 2011), while BDNF therapy results in increased synaptic efficiency and plasticity (Murer et al., 2001; Nagahara et al., 2009; Budni et al., 2015) and increased neuronal survival (Arancibia et al., 2008).