Monomeric CRP (mCRP), a dissociation product of pCRP under immune-inflammatory conditions, exhibits pro-inflammatory effects; however, it has not been investigated in MDD or its subtypes, major dysmood disorder (MDMD) and simple dysmood disorder (SDMD).<h4>Objective</h4>To examine serum mCRP, albumin, transferrin, M1 macrophage and Thelper-17 immune profiles, and adverse childhood experiences (ACEs) in MDD, MDMD and SDMD.<h4>Methods</h4>Seventy-nine MDMD patients, 30 SDMD patients, and 40 controls were included. The gene discussed is CRP; the disease is major depressive disorder.