Fig 1: Brain-derived neurotrophic factor (BDNF) Levels in astrocyte-derived extracellular vesicles (ADEVs) of MDD and HCs Under Various Normalization Strategies (A–H). (I) Receiver operating characteristic (ROC) curves of target proteins in ADEVs. The results showed that the area under the curve (AUC) for BDNF/CD9 was 0.738, with a sensitivity of 80.0% and a specificity of 66.7%, while the AUC for BDNF/CD81 was 0.756, with a sensitivity of 93.3% and a specificity of 53.3%. Note: n.s: not significant; *P < 0.05