PHEX and major depressive disorder: Increasing evidence suggests a close association between carbohydrate metabolism and depression, with abnormalities in carbohydrate metabolism being observed in the PFC (Baxter et al., 1989; Kennedy et al., 2001; Hennings et al., 2012; Li et al., 2015; Yao et al., 2023), HIP (Cherix et al., 2022), and HYP (Al-Massadi et al., 2021) of depression patients or depression-like animal models.