“…A review study showed a significant association between DNA methylation and depression risk. Hypermethylation of BDNF, CRMP2, NR3C1, and SLC6A4 is associated with Depression and MDD ( Xiang et al, 2021 , Li et al, 2021 , Borçoi et al, 2021 , Li et al, 2019 , Schiele et al, 2021 , Sanwald et al, 2021 , de Assis Pinheiro et al, 2021 ). Several studies have investigated DNA methylation of some critical genes modulating depressive symptoms, including PTPRN2 (correlated with mood state disturbances), HES5 (associated with MDD and suicide), GATA2 (related to depressive behavior in rats), DGKA (differed significantly between MDDs and controls), NIPA2 (increased risk of MDD), PRDM7 (important in aging and Alzheimer), KCNIP1 (regulate neuronal membrane excitability), GRIK2 (related to mood disorders and depressive symptoms) ( Wang et al, 2021 ).…”