Of them, NR1D1 genetic variants have been demonstrated to associate with bipolar disorders (21–23) and depressive disorders (24, 25), CRY2 (cryptochrome 2) with depressive disorders (26, 27) and bipolar disorders (28), and CRY1 (cryptochrome 1) with depressive disorders (29). Here, NR1D1 is linked to bipolar disorder.