Neuro Variability: Advanced trial-by-trial analysis of TMS-EEG in depressive disorder

Stimulus-evoked brain activity exhibits inadequate understanding among researchers regarding its relationship to abnormal neural variability in depressive disorder. The research develops a modern computational system which evaluates trial-by-trial variability in transcranial magnetic stimulation-evoked EEG signals to analyse neurophysiological dysfunction in depressive disorder. TMS-EEG measurements came from 40 participants with depressive disorder and 40 neurotypical controls (HC). This maximum eigenvalue analysis of real binary correlation matrix enhanced by cross-correlation models generated surrogate results which yielded 92.8% accuracy in characterizing DE and HC subjects with sensitivity at 91.5% and specificity at 94.2%. The analysis found DE patients had substantially less TTV during Gamma band conditions while showing higher TTV within Delta band ranges compared to healthy control participants. TMS-EEG data showed that HAMD-17 scores correlated negatively with the Gamma-band TTV measure which establishes potential clinical usage as a depression severity indicator. This research establishes foundational knowledge about using TTV to detect depression-linked neural activities through TMS-EEG data processing while introducing a precise identification method. This research establishes foundations which will guide future investigations aimed at identifying diagnostic biomarkers along with neuromodulation techniques for the treatment of depressive disorders.