40 medication-free Depressed Patients will receive a battery of neuropsychologic tests, standard dichotic listening tests, EEG, ERP and an f-MRI while performing a neuropsychologic test, the Simon. Once testing is completed, patients will be treated in an open treatment trial of SSRI. Non-responders will then receive Bupropion followed by Tricyclic Antidepressant if still depressed. While our main purpose is to correlate imaging testing with other measures of brain functioning, we also intend to see whether f-MRI findings demonstrate specific brain areas which differ between responders and non-responders. At the end of SSRI treatment, patients will have a second f-MRI scan to investigate any changes treatment and/or response may have caused.