This study will measure the activity in different parts of the brain, while the patients are seeing some pictures, using Magnetic Resonance Imaging (MRI) scan. For this study three MRI scans will be conducted. One before the patient begins on any medication, one during the study after 3 weeks of treatment and one after six more weeks of treatment with a standard antidepressant called Escitalopram(trade name: Lexapro).
