According to the differentially expressed genes (DEGs) analysis, we identified a total of 48 DEGs across various T cell subsets by comparing MDD patients with psychiatrically healthy controls, and 33 of these DEGs were specifically from CD8+ TSCM cells, indicating that these cells in MDD patients exhibit the most significantly distinct transcriptional profile (Fig. 2C and Supplementary Data 7). This evidence concerns the gene CD8A and major depressive disorder.