BDNF and major depressive disorder: The exact etiology and pathogenesis of depression remain unclear; however, recent research has shown that the inflammatory response may be involved, with interleukins such as IL‐1β and IL‐10 being strongly implicated, along with the modulation of genes BDNF, VEGF, and GluN2B in the hippocampus and cortex of animal models of depression [3, 4].