This fits with evidence from others suggesting that BDNF is negatively correlated with depression (Sen et al., 2008; Polyakova et al., 2015) as well as emotional exhaustion and depersonalization (Onen Sertoz et al., 2008) and increases in association with successful treatment of depression (Polyakova et al., 2015). Here, BDNF is linked to major depressive disorder.