The goal of this research is to identify biomarkers that will help us to understand why and how some people respond to treatment for depression while others do not. This project will include 60 adult patients with major depression that have been independently scheduled to receive ECT as part of their course of treatment. We will also include 30 subjects without depression for comparison. This research is funded by the National Institutes of Health and the UCLA Integrative Mood Disorders Center and Cousins Center for Psychoneuroimmunology. Participation is entirely voluntary and kept confidential.