CKB and major depressive disorder: As for the relationship of depression with CVD, our result (HR = 1.40, 95% CI, 1.09–1.81) was similar with CKB (HR = 1.33, 95% CI, 1.15–1.53) [19] and CHARLS study (HR = 1.39, 95% CI, 1.22–1.58) [40].