S100B and major depressive disorder: Figure 4A displays the AUC value of BDNF, VEGF, and S100B at 0.799 (95% CI: 0.739∼0.850), 0.668 (CI: 0.600∼0.730), and 0.706 (95% CI: 0.640∼0.766), respectively, for distinguishing MDD patients from controls in all OA participants.