SIRT1 and depressive disorder: Animal experiments revealed that chronic stress led to a reduction in SIRT1 expression in the dentate gyrus (DG) of the hippocampus of mice, inducing depression-like behaviors [3]; injection of SIRT1 activator resveratrol (RSV) in the hippocampus of depressed mice alleviated the depressive symptoms [4]; in addition, infusion of SIRT1 inhibitor, EX-527, into the medial prefrontal cortex of depressed mice reversed the antidepressant effect of S-ketamine [5].