Further research is needed to examine the moderating and mediating effects of BMI on depression with additional biomarkers, e.g., malondialdehyde, F2-isoprostanes, 8-hydroxy 2′-deoxyguanosine, neuropeptide Y, adiponectin, IL-6, TNF-α, and IL-17. The gene discussed is NPY; the disease is major depressive disorder.