Inclusion criteria for depressed patients:
- Diagnostic and Statistical Manual of Mental Disorders 4th Edition (DSM-IV) diagnosis of Unipolar Major Depressive Disorder with or without psychotic features.
- 21-item Hamilton Depression Rating Scale (HDRS) score greater than or equal to 21.
- Thase Core Endogenomorphic Scale score greater than or equal to 8 on the items included in the 21-item HDRS.
- Between 18 - 70 years of age.
- If currently taking antipsychotic, antidepressant, anticonvulsant, and/or mood-stabilizing medications, must be stable on the medication for at least one-week prior to entering the study.
- Pre-existing (current) primary treating psychiatrist for subjects with psychotic features.
- Any secondary diagnoses from the anxiety disorder spectrum is acceptable. Primary pre-existing chronic Obsessive-Compulsive Disorder (OCD) will be an exclusion criteria.
Inclusion criteria for healthy controls:
- Between 18 - 70 years of age.
- Have a HAM-D score of less than or equal to 5.
Exclusion Criteria for depressed patients:
- Electroconvulsive Therapy (ECT) in the 6 months prior to the study.
- Abuse of drugs or alcohol in the 6 months prior to study.
- Unstable or untreated hypertension or cardiovascular disease.
- Use of additional prescription medications, street drugs, or alcohol during the week before the study.
- Any Axis II diagnosis or traits which would make participation in the study difficult.
- Current pregnancy or lactation.
- Post-partum depression
- Diagnosis of obsessive-compulsive disorder
- History of significant cognitive decline
Exclusion criteria for healthy controls:
- Personal history of Axis I or Axis II disorders.
- Active unstable medical problems.
- Abuse of drugs or alcohol in the 6 months prior to study.
- Use of additional prescription medications, street drugs, or alcohol during the week before the study.
- Currently pregnant or lactating.
- History of significant cognitive decline