CXCL8 and major depressive disorder: Our data from the present cross-sectional study further revealed that increased serum IL-8 levels might be implicated in the MDD psychopathology or the use of SSRIs, and elevated serum IL-8 levels contributed to improving delayed memory and visuospatial/constructional function of MDD, and cognitive function in patients with SSRIs was impaired in comparison to healthy controls.