This study will investigate the use of deep brain stimulation (DBS) to reduce symptom severity and enhance the quality of life for patients with treatment-refractory major depression.

Despite advances in pharmacotherapy and psychotherapy for major depression, a substantial number of patients fail to improve significantly even after years of conventional and experimental interventions. Bilateral deep brain stimulation (DBS) to the region of the anterior capsule/ventral striatum is an adjustable and reversible procedure that may be a more effective treatment for patients with major depression. This study will determine the effectiveness, safety, and tolerability of DBS in patients with treatment-refractory major depression.

Inclusion Criteria:

• Major depression (MD), severe, unipolar type

• German mother tongue

• Hamilton Depression Rating Scale (HDRS24) score of > 20

• Global Assessment of Function (GAF) score of < 45

• At least 4 episodes of MD or chronic episode > 2 years

• > 5 years after first episode of MD

• Failure to respond to *adequate trials (>5 weeks at the maximum recommended or tolerated dose) of primary antidepressants from at least 3 different classes;

  • adequate trials (>3 weeks at the usually recommended or maximum tolerated dose) of augmentation/combination of a primary antidepressant using at least 2 different augmenting/combination agents (lithium, T3, stimulants, neuroleptics, anticonvulsants, buspirone, or a second primary antidepressant); *an adequate trial of electroconvulsive therapy [ECT] (>6 bilateral treatments) and; *an adequate trial of individual psychotherapy (>20 sessions with an experienced psychotherapist).

• Able to give written informed consent

• No medical comorbidity

• Drug free or on stable drug regimen at least 6 weeks before study entry

Exclusion Criteria:

• Current or past nonaffective psychotic disorder
• Any current clinically significant neurological disorder or medical illness affecting brain function, other than motor tics or Gilles de la Tourette syndrome
• Any clinically significant abnormality on preoperative magnetic resonance imaging (MRI)
• Any surgical contraindications to undergoing DBS
• Current or unstably remitted substance abuse (aside from nicotine)
• Pregnancy and women of childbearing age not using effective contraception
• History of severe personality disorder