CXCL8 and depressive disorder: Mood states: POMS (anxiety (+), depression (+), anger (+), vigor (/), fatigue (/), confusion (/));Inflammatory cytokine: IFN-γ (+), IL-6 (+), IL-8 (+), IL-1β (+), TNF-α (/), CRP (+);Lymphocytes and subsets: NK cell (+), NK-like cell (+), CD8+ T-cell (+);Stress hormones: Cortisol (+), epinephrine (+)