Amplitude Titration to Improve ECT Clinical Outcomes

A randomized controlled trial will compare hippocampal neuroplasticity, antidepressant, and cognitive outcomes between individualized amplitude and fixed 800 mA amplitude ECT in older depressed subjects (n = 25 per group, n = 50 total). Relative to fixed 800 mA ECT:H1: Individualized amplitude arm will have improved RUL antidepressant outcome (IDS-C30 response rates and reduced BT electrode placement switch at V2).H2: Individualized amplitude arm will have improved cognitive outcomes (DKEFS-Verbal Fluency

Inclusion Criteria:Diagnosis of major depressive disorder or bipolar IIClinical indications for ECT with right unilateral electrode placementExclusion Criteria:Defined neurological or neurodegenerative disorder (e.g., traumatic brain injury, epilepsy, Alzheimer's disease)Other psychiatric conditions (e.g., schizophrenia, bipolar I disorder)Current drug or alcohol use disorder (except for nicotine)Contraindications to MRI.