Patients with MDD in the remission phase revealed increased blood levels of inflammatory markers [10], decreased serotonin transporter binding in platelets and lymphocytes, hypercortisolemia, and hypocholesteremia, the reduced concentration of brain-derived neurotrophic factor (BDNF), and the decreased phosphorylation of cAMP response element-binding protein (CREB) [8,11]. Here, BDNF is linked to major depressive disorder.