Metabolomics During ElectroConvulsivoTherapy

This study is examining how electroconvulsive therapy (ECT) — a well-established treatment for severe, treatment-resistant depression that involves brief electrical stimulation of the brain — changes the body's metabolic profile (the chemicals present in the blood) over the course of treatment. ECT is highly effective for some patients who have not responded to antidepressants. This research may help identify biological markers that predict who will respond to ECT. **You may be eligible if...** - You have been diagnosed with a major depressive episode that meets DSM-5 criteria - You have a diagnosis of major depressive disorder or bipolar disorder - Your depression is severe enough to qualify for ECT (MADRS score above 22) - At least 2 antidepressants have failed to work for you at an effective dose for at least 6 weeks each - You have been recommended for ECT by your doctor and are not under any legal protective order **You may NOT be eligible if...** - Your ECT is needed for a vital emergency and there is no time to consent - You have schizophrenia or other psychotic disorders unrelated to depression - You have neurological conditions such as epilepsy, multiple sclerosis, or Parkinson's disease - You have an acute or chronic systemic inflammatory disease requiring immunomodulatory treatment - You are detained by a judicial or administrative authority Talk to your doctor to see if this trial is right for you.