Early Brainwave Biomarkers for Personalized Neuromodulation in Treatment-resistant Depression

Inclusion Criteria: * Aged 18-65 years * Clinical diagnosis of Major Depressive Disorder (MDD), confirmed by structured clinical interview * Current moderate-to-severe depressive episode (MADRS score ≥ 20) * Moderate-to-severe treatment resistance, assessed using the Maudsley Staging Method * Able to comprehend English sufficiently to complete study procedures and assessments * Able to maintain stable antidepressant regimen or remain medication-free for at least 4 weeks prior to and during the study Exclusion Criteria: * Primary psychiatric diagnosis other than MDD * Contraindications to MRI (e.g., implanted metal) * Conditions or medications that may increase risk associated with TMS * Prior exposure to repetitive TMS (rTMS) * Non-response to electroconvulsive therapy (ECT) * History of psychosurgery for depression * High suicidal risk as assessed by the Columbia Suicide Severity Rating Scale (C-SSRS)