Levels of CRP (g = 0.71; 95%CI: 0.50–0.92; p < 0.0001); IL-3 (g = 0.60; 95%CI: 0.31–0.89; p < 0.0001); IL-6 (g = 0.61; 95%CI: 0.39–0.82; p < 0.0001); IL-12 (g = 1.18; 95%CI: 0.74–1.62; p < 0.0001); IL-18 (g = 1.97; 95%CI: 1.00–2.95; p < 0.0001); sIL-2R (g = 0.71; 95%CI: 0.44–0.98; p < 0.0001); and TNFα (g = 0.54; 95%CI: 0.32–0.76; p < 0.0001) were significantly higher in patients with depression. Here, IL18 is linked to major depressive disorder.