Inclusion Criteria:

• Subjects will be adults, ages 18 to 55 years;
• Able to provide written informed consent;
• MDD, current according to the fourth version of the Diagnostic and Statistical Manual for Mental Disorders (DSM-IV);
• QIDS-SR score of > 12 at screen;
• Current major depressive episode (MDE) length of < 1 year;
• Treated with an SSRI or SNRI at adequate doses (defined as 20 mg/day or more of fluoxetine, citalopram, or paroxetine; 10 mg/day or more of escitalopram; 50 mg/day or more of sertraline; 75 mg/day or more of venlafaxine; 15 mg/day of mirtazapine; or 40 mg/day of duloxetine) during the current episode for at least 8 weeks; and,
• At the time of screen visit, patients must be on a stable dose of SSRI or SNRI for the past 4 weeks.

Exclusion Criteria:

• Pregnant women or women of child bearing potential who are not using a medically accepted means of contraception (to include oral contraceptive or implant, condom, diaphragm, spermicide, intrauterine device, tubal ligation, or a partner with vasectomy). Women of childbearing age who wish to enter the study will be required to undergo a pregnancy test (beta-HCG) prior to initiating treatment;
• Patients who, in the investigator's judgment, pose a current, serious suicidal or homicidal risk. These patients will be immediately referred to appropriate clinical treatment;
• Patients who, in the opinion of the therapist, are not depressed at the time of their first psychotherapy visit;
• Patients who are currently being treated by a psychotherapist individually or in a group or who have received individual or group psychotherapy during the past 6 months. Couples therapy and family therapy will not be considered exclusionary criteria;
• Patients with neurological illnesses, including a history of seizure or head trauma with loss of consciousness;
• Patients with unstable diabetes, kidney disease, or significant medical illness;
• Patients with history of allergy to FDG will be excluded from taking part in the PET portion of the study;
• The following DSM-IV diagnoses: substance use disorders active within the last six months, any bipolar disorder (current or past), any psychotic disorder (current or past), any post-traumatic stress disorder (current or past), any obsessive compulsive disorder (current or past), or any panic disorder (current or past). Generalized anxiety disorder or adjustment disorder are not exclusionary;
• Patients currently requiring other psychotropic medications, including anticonvulsants, benzodiazepines, antipsychotics, stimulants, or sedative hypnotics (other than diphenhydramine);
• Psychotic features in the current episode, or a history of psychotic features, as assessed by SCID;
• Patients who have undergone > 3 previous adequate attempts at psychodynamic psychotherapy (deemed "adequate" by the screening physician), which were considered unhelpful or unsuccessful by patient report (according to patient report);
• Patients with a history of antidepressant-induced hypomania; and
• Patients with a history of medication non-compliance.
• Patients with Axis II pathology (personality disorder) that, in the opinion of the screening physician, would interfere with subjects' ability to participate in the treatment and/or comply with the protocol, such as severe borderline or narcissistic personality disorder.
• Patients who have had electroconvulsive therapy (ECT) within the 12 months preceding baseline