The diagnostic value of the candidate genes(LYPD1,HMBS,HEBP2,SETD3 and ECM2)distinguishing BD from MDD was then evaluated using ROC curves, which were (AUC 0.89, CI 0.99–0.78) in GSE92538-GPL10526 (Fig. 9A); (AUC 0.77, CI 0.87–0.68) in GSE92538-GPL17027 (Fig. 9B); and (AUC 0.77, CI 0.87–0.68) in the combined dataset was (AUC 0.73, CI 0.81–0.65) (Fig. 9C). Here, ECM2 is linked to major depressive disorder.