Predictive value of EEG/ECG biomarkers for treatment response in depression

Major depressive episodes frequently show limited response to first-line treatments, motivating the search for objective biomarkers. EEG/ECG-based support tools aggregating electrophysiological predictors may guide treatment selection. We examined whether antidepressant treatments concordant with an EEG/ECG-biomarker report were associated with higher response rates.

We retrospectively analyzed adults with ICD-10 depressive disorder or bipolar depression treated with electroconvulsive therapy (ECT), repetitive transcranial magnetic stimulation (rTMS), (es)ketamine, or selective serotonin reuptake inhibitors (SSRIs) between 2022 and 2024. Resting-state EEG with simultaneous ECG generated individualized biomarker reports with modality-specific response likelihoods. Treatment chosen by clinical teams was classified as concordant or non-concordant; response was derived from routinely collected clinical scales.

Among 153 patients (ECT n = 53, rTMS n = 48, (es)ketamine n = 36, SSRIs n = 16), response rates were higher for concordant vs non-concordant treatments: ECT 70% vs 50%, rTMS 30% vs 13%, (es)ketamine 31% vs 10%, and SSRIs 100% vs 11%. Overall, 46% (42/92) of concordant vs. 26% (14/54) of non-concordant patients responded (absolute difference + 20 percentage points; relative increase ≈77%; number needed to treat ≈5).

Concordance with EEG/ECG biomarkers correlated with higher treatment response, warranting confirmation in prospective trials.

EEG/ECG-based decision support may enhance antidepressant treatment response in everyday clinical practice.