Although significantly lower BDNF had great discriminative accuracies for CP (AUC=0.82, 95% CI=0.72 to 0.93, p=0.05), plasma BDNF had a comparatively much poorer discriminative accuracy for both MDD and GAD (AUC=0.62, 95% CI=0.49 to 0.75, p=0.478) and (AUC=0.47, 95% CI=0.22 to 0.72, p=0.829), respectively. The gene discussed is BDNF; the disease is major depressive disorder.