Aperiodic (1/f) Neural Activity Robustly Tracks Symptom Severity Changes in Treatment-Resistant Depression.

Background: A reliable physiological biomarker for major depressive disorder is essential for developing and optimizing neuromodulatory treatment paradigms. In this study, we investigated a passive electrophysiologic biomarker that tracks changes in depressive symptom severity on the order of minutes to hours.

Methods: We analyzed brief recordings from intracranial electrodes implanted deep in the brain during a clinical trial of deep brain stimulation for treatment-resistant depression in 5 human participants (n = 3, n = 2).