Phase synchronization alterations of EEG oscillations during emotional video processing in depression and anxiety: a...

Emerging evidence indicates overlapping neurobiological variations across transdiagnostic psychiatric disorders. Considering depression and anxiety as the most common and co-occurring symptoms in affective disorders, we hypothesize shared symptom-related electrophysiological aberrations in the neural rhythmic oscillations across diagnostic boundaries.

53 treatment-naïve patients with major depressive disorder, generalized anxiety disorder, or depressive episode in bipolar disorder, and 83 healthy controls (HC), underwent 64-channel electroencephalographic (EEG) recording while watching 10 min of neutral, sad, happy and fearful videos. The phase locking value (PLV) based on individual alpha peak frequency (iAPF) was used to measure phase synchronization alteration of EEG oscillations.

Compared with HCs, patients exhibited widespread phase synchronization disturbances, characterized by prominent gamma PLV reductions and low-frequency (delta/theta/alpha) increases across frontal, central, and parietal-occipital regions. Depressive symptoms correlated with decreased beta PLV in the central region during happy stimuli, increased alpha PLV in the parieto-occipital lobe during sad stimuli, and increased theta PLV in the frontal and parietal lobes during fearful stimuli. Anxious symptoms correlated with decreased gamma PLV in the right frontal and parietal lobes during happy stimuli, increased alpha PLV in right frontal and parietal lobes, and increased gamma PLV in the frontal and parietal lobes during fearful stimuli.

This study supports shared symptom-related aberrations in EEG phase synchronization patterns across transdiagnostic affective disorders, as well as the divergent neural characteristics between depression and anxiety. These findings may provide potential implications for probing and modulating symptom-targeted neural oscillational biomarkers across diagnoses.