CCL2 and major depressive disorder: For the whole study population, the HADS depression score showed a positive correlation with IP-10 and MCP-1 (p ​= ​.008, ρ ​= ​0.211; and p ​= ​.008, ρ ​= ​0.212), and negative correlation with IL-1β, IL-4, IL-6, TGF-β1, TGF-β2, TGF-β3, and TNF-α (p ​= ​.010, ρ ​= ​−0.204; p ​< ​.001, ρ ​= ​−0.252; p ​= ​.010, ρ ​= ​−0.206; p ​= ​.001, ρ ​= ​−0.264; p ​< ​.001, ρ ​= ​−0.295; p ​= ​.001, ρ ​= ​−0.264; and p ​< ​.012, ρ ​= ​−0.199 respectively).