We found that activated dendritic cells, immature dendritic cells, monocytes, and neutrophils were higher, and activated B cells, activated CD4 T-cells, effector memory CD8 T-cells, and immature B cells were lower in MDD patients compared with healthy controls, with similar to Pfau’ (Pfau et al., 2018) and Kronfol’s studies (Kronfol, 2002). Here, CD4 is linked to major depressive disorder.