DRD2 and major depressive disorder: CCHP treated depression by acting on multiple key targets, such as AKT1, IL-6, TP53, DRD2, MAPK1, NR3C1, TNF, ESR1, SST, OPRM1, DRD3, ADRA2A, and ADRA2C, and through important biological processes, such as positive regulation of transcription from RNA polymerase II promoter, plasma membrane, and protein binding.