The two groups did not differ in age, gender ratio, education or global cognition (Mini-Mental State score6) but the depression group had significantly higher blood CRP levels than controls (mean CRP: depression group 18.8 mg/L, control group 1.2 mg/L; P = 0.002) and a trend in Montgomery–Åsberg Depression Rating Scale7 score (depression group 10.0, control group 4.0; W = 13.5, P = 0.065). This evidence concerns the gene CRP and major depressive disorder.