SIRT1 is a target of many types of miRNAs (Bicker and Schratt, 2010; Gao et al., 2010; Saunders et al., 2010; Yamakuchi, 2012; Zhou et al., 2012; Ahn et al., 2013; Chaudhuri et al., 2013a; Choi and Kemper, 2013), although miRNA-mediated regulation of SIRT1 in depression has not been fully understood. This evidence concerns the gene SIRT1 and major depressive disorder.