Chronic Major Depression, Recurrent

The purpose of the study is to identify brain biomarkers and characteristics that predict individual responses to treatment of major depression with the antidepressant drug sertraline (tradename Zoloft), a common selective serotonin reuptake inhibitor (SSRI) antidepressant. Our central hypothesis is that brain activity and connections jointly measured with functional magnetic resonance imaging (fMRI) and electroencephalogram (EEG) will be able to predict an individual's response to sertraline treatment.