DDIT4 and major depressive disorder: DDIT4 levels were elevated in MDD patients and had been verified to be related to neuronal atrophy and depressive behavior caused by chronic stress (Malagelada et al., 2011; Ota et al., 2014; Wang et al., 2018; Perez-Sisques et al., 2021); S100B levels were also elevated in MDD patients, and associated with glial cell dysregulation (Gos et al., 2013; Güleş et al., 2020; O’Leary and Mechawar, 2021; Zhang et al., 2021).