VA Augmentation and Switching Treatments for Improving Depression Outcomes

Inclusion Criteria: * DSM-IV diagnosis of single or recurrent, non-psychotic, major depressive disorder * Currently taking a selective serotonin reuptake inhibitor (SSRI) or serotonin-norepinephrine reuptake inhibitor (SNRI) or mirtazapine for major depressive disorder * Need for "next-step" treatment based on documented suboptimal outcome from current antidepressant treatment for major depressive episode (at least 6 weeks treatment with a QIDS-C16 \>= 16 or at least 8 weeks with a QIDS-C16 \>= 11; and at least 3 weeks at a stable "optimal" dose * Age: 18 years of age or older Exclusion Criteria: * Prior inadequate response after an adequate treatment trial or clear cut intolerance to either of the study medications (aripiprazole or bupropion) * Current treatment with bupropion, aripiprazole or any other antipsychotic agent * Lifetime history of bipolar disorder, schizophrenia, schizoaffective disorder, or psychosis not otherwise specified * Current diagnosis of Dementia * Current diagnosis of an eating disorder or a seizure disorder * High suicide risk currently requiring acute intervention (other than outpatient treatment of depression) * Unstable, serious medical condition or one requiring acute medical treatment, or anticipation of hospitalization for extended care * Requiring immediate hospitalization for psychiatric disorders * Physiologic substance dependence requiring detoxification (excluding nicotine) in the past 30 days (substance abuse is not an exclusion crite…