Both additive interaction (attributable proportion (AP) = 0.56; 95% CI: 0.24-0.90 and synergy index (SI) = 4.39; 1.0-18.7) and multiplicative interaction (log likelihood test p = 0.1) was present between depression and COMT Val158Met in predicting risk of later CVD. Here, COMT is linked to major depressive disorder.