Patients with MDD displayed increased MPV, PLR, RPR and RDW values, and decreased paltelet, neutrophil, lymphocyte, albumin, PDW, PCT and SII values; patients with BD showed increased MPV, neutrophil, RDW, RPR and SII values, and decreased platelet, PDW, PCT, albumin and PLR values. The gene discussed is ALB; the disease is major depressive disorder.