Directed Functional Connectivity Based on EEG During Emotional Music Perception for Major Depressive Disorder...

Major depressive disorder (MDD) is associated with impaired emotional processing and dysregulation of large-scale brain networks. While electroencephalography (EEG) studies have reported altered functional connectivity in depression, the directional organization of information flow during emotional processing remains insufficiently characterized. This study investigated emotion-evoked directed functional connectivity (DFC) during emotional music perception in individuals with MDD using EEG. EEG data were collected from 18 individuals with MDD and 18 healthy controls while listening to music with positive, neutral, and negative emotional valence. Frequency-specific DFC patterns were estimated using the directed transfer function. Group differences were assessed using generalized estimating equations and non-parametric permutation tests, and associations between DFC features and depressive symptom severity were examined using partial correlation analysis. A subject-level validation framework was employed to evaluate the discriminative properties of DFC features that demonstrated both group-level differences and clinical relevance. The results showed a significant increase in delta-band DFC strength in individuals with MDD across all emotional music conditions, with spatially distributed alterations in the frontal, central, and parieto-occipital regions. Under the positive music condition, delta-band DFC features were significantly associated with depressive symptom severity and reliably distinguished individuals with MDD from healthy controls at the individual level. In addition, behavioral analysis revealed significant negative correlations between music liking ratings and depressive symptom severity. These findings characterize task-evoked alterations in directional brain network organization during emotional music processing in MDD and support the utility of EEG-based DFC analysis for system-level investigation of affective network dysfunctions.