GFAP and major depressive disorder: Peripheral GFAP and S100β are crucial biomarkers indicative of the extent of neuroinflammation and neuronal damage (Steinacker et al., 2021; Zozulya et al., 2021), and they have been established as integral factors in the pathophysiology of MDD (Shi et al., 2020b; Levchuk et al., 2023; Zhao et al., 2024).