CD2 and major depressive disorder: In addition, in the CD2 category, the high FRE+DUR30, the high FRE+DUR0, the low FRE+DUR30, and the low FRE+DUR0 showed ~5.5-fold, ~9.3-fold, ~6.2-fold and ~11.1-fold increased risk of depression, respectively (p < 0.001).