TNF and major depressive disorder: Patients with MDD had significantly higher serum levels of IL-1 beta (0.17 ± 0.13 versus 0.09 ± 1.22 pg/ml, p < 0.001) and of TNF-alpha (0.72 ± 0.23 versus 0.62 ± 0.22 pg/ml, p = 0.013), while levels of hsCRP (1.91 ± 3.02 versus 1.60 ± 2.24 mg/l) were similar between groups.