TNF and depressive disorder: TNF-α: Tumor Necrosis Factor Alpha; NLRP3: Nod-like receptor pyrin-containing 3; IFN-γ: interferon gamma; hsCRP: high-sensitivity C-reactive protein; MDD: major depressive disorder; TRD: treatment-resistant depression; CKD: chronic kidney disease; LPS: lipopolysaccharide; PHA: phytohemagglutinin; CHD: coronary heart disease.