Major depressive disorder (MDD) is a common psychiatric illness with a high cost to society and individual patients. Initial medication treatments for MDD are often ineffective, precipitating a need to try other medications. This extends suffering, continues functional disability, and increases both the risk of relapse and the risk that people will abandon treatment. Having a biological marker of likely treatment effectiveness to predict and guide clinicians' decisions would reduce the likelihood of people with MDD experiencing unsuccessful treatments. This study will test whether quantitative electroencephalogram (QEEG) measures taken after 1 week of medication treatment can predict effectiveness of a full treatment regimen with depression medications.~Participation in this study will last 8 weeks. At the first study visit, participants will undergo baseline assessments. These assessments will include an interview about present condition, medical and psychiatric history, and past and current medication treatments; a urine test; and questionnaires about depression symptoms and other possible symptoms. The study doctor may ask for other assessments based on each participant's individual profile.~Participants will then complete a 1-week treatment with escitalopram, a type of antidepressant medication called a selective serotonin reuptake inhibitor (SSRI). At the first visit and again after the week-long escitalopram treatment, participants will undergo an electroencephalogram (EEG), which measures brain electrical activity. Based on certain measurements obtained from the EEG, an antidepressant treatment response (ATR) score will be calculated.~Participants will then be divided into two treatment groups: those who continue to receive escitalopram and those who begin treatment with bupropion XL, a non-SSRI antidepressant medication. Treatment for both groups will last 8 weeks, during which time participants will attend seven study visits. At these study visits, participants will be asked about how they are feeling, side effects, and benefit from the treatment. Further tests-such as a physical exam, lab test, or EEG-may be performed if study doctors think they are necessary.
This study will examine whether measures of brain electrical signals taken after a week of antidepressant medication treatment can predict whether a full treatment regimen will be effective.