Specifically, both MDD-High (Wilcoxon p = 0.004, d = 0.65) and MDD-Low (Wilcoxon p = 0.046, d = 0.53) showed higher leptin concentrations than HC, while there was no difference between MDD-High and MDD-Low (Fig. 1A). The gene discussed is LEP; the disease is major depressive disorder.