Of thirteen depression‐associated DRPs, seven proteins including DDC, FGFR2, KIBRA, MED22, OLIG1, RAI1, SLIT2 were upregulated, whereas six proteins including COX3, CRHBP, CSMD1, FSTL1, GRIK4, and LMTK3 were downregulated (Figure 6B). Here, DDC is linked to major depressive disorder.