We demonstrate that numerous immune-related and metabolic pathways are activated in MDD patients with CRP > 1 mg/L (that is, CRP 1–3 and >3) vs. controls or MDD with CRP < 1 mg/L, while MDD with CRP values < 1 mg/L show inhibition of cell-cycle-related pathways vs. controls. Here, CRP is linked to major depressive disorder.