The main purpose of this study is to correlate brain testing with treatment outcome.

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.

Inclusion Criteria:

• DSM-IV Major Depression or Dysthymia
• Age 18-65
• Physically healthy
• Normal hearing
• Drug-free (two weeks for most antidepressants, four weeks for Fluoxetine)

Exclusion Criteria:

• Hearing deficit in one or both ears
• Body metal (e.g., wire stitches, screws in bones, stainless steel hips)
• History of Psychosis or Epilepsy
• Current (past six months) Substance Use Disorder (illicit drugs and/or alcohol)
• Unstable medical problem
• Insufficient English for neuropsychological and dichotic testing
• Bipolar I
• Need for wash-out from effective treatment in order to participate
• Pregnant
• High suicide risk
• Currently taking (within 2 weeks; 4 weeks for Fluoxetine) antidepressants