Cross-sectional inflammatory correlations with PHQ scores firstly support previous evidence that inflammatory dysregulations are greater in those with more severe depression, with significant associations emerging for markers implicated in treatment response as discussed above (TNFa, sICAM1, IL-6, TARC, MCP4 and IFNy) as well as related proteins Mip1b, MCP1, SAA [17,18,21]. Here, CCL4 is linked to depressive disorder.