Inclusion Criteria:

1. Men and women aged 18-80 years, inclusive.
2. Drug-free outpatients or inpatients meeting DSM-IV criteria for major depression with psychotic features.
3. Inpatients who undergo a 5-7 day washout period of their medication while concurrently beginning one of the approved SSRI's and abilify.
4. HAM-D-24 score > 16.

Exclusion Criteria:

1. Pregnant women and women of child bearing potential not using a medically accepted means of contraception (oral contraceptives are allowed).
2. Women who are breast-feeding.
3. Patients meeting DSM-IV criteria for major depression without psychotic features, or psychosis without major depression at the screen visit.
4. Patients with serious suicidal risk.
5. Patients with a history of seizure disorder; unstable physical disorders (cardiovascular, hepatic, renal, respiratory, endocrine, neurologic, or hematologic); or any physical disorder judged to significantly affect central nervous system function.
6. Patients meeting criteria for the following DSM-IV diagnoses: organic mental disorders; substance use disorders, including alcohol, active within the last 6 months; bipolar disorder; schizoaffective disorder; or antisocial personality disorder.
7. Patients who are currently taking an antidepressant, antipsychotic, or mood stabilizing drug and who are responding to one or all of these medications. If patients are not responding to these medications, they may go through a washout period of at least one week under the supervision of a study doctor before entering into this study.
8. Patients who are not able to read and understand the consent form, or who are not capable of understanding or giving informed consent to the procedures of the study