This finding is in agreement with the hypothesis of a cross-regulation between BDNF and cytokine production [8] and supported by the several reports: 1) inflammation induced-anxiety and depression with decreased hippocampal expression of BDNF in rats [62]; 2) inflammation-dependent decrease in BDNF in depression [10]; 3) chronic schizophrenia [63]; 4) normalization or up-regulation of BDNF levels in response to antidepressant [64] and 5) antipsychotic treatments [65]. Here, BDNF is linked to major depressive disorder.