The MDD group exhibited significantly higher levels of IL-1ra (p = 0.006, d = 0.657), IL-6 (p = 0.014, d = 0.596), CRP (wilcoxon p < 0.001, d = 1.186), and leptin (wilcoxon p = 0.021, d = 0.637) than HC. Here, IL6 is linked to major depressive disorder.