While in clinical trials, a blood test of 50 patients with major depression reported that the expression of the SIRT1 gene in peripheral blood was 37% lower than that in the control group [6], and the mutation of the SIRT1 rs10997875 gene locus was positively correlated with the number of patients with depression and the degree of depression [7]. The gene discussed is SIRT1; the disease is depressive disorder.