Efficacy Study of Deep Brain Stimulation in Patients With Treatment Resistant Major Depression

Inclusion Criteria:

1. Major depression (MD), severe, unipolar, or bipolar in an acute depression episode.
2. German mother tongue or fluent.
3. Male or female patients ≥20 and ≤75 years.
4. Hamilton Depression Rating Scale (HDRS-28) score of >21.
5. Global Assessment of Function (GAF) score of <45.
6. At least 4 episodes of depression or one chronic episode >2 years.
7. Failure to respond to
8. adequate trials of primary antidepressants from at least 3 different classes (>5weeks at the maximum recommended or tolerated dose) and
9. adequate trials of augmentation/combination of a primary antidepressant (>3 weeksat the usually recommended or maximum tolerated dose) using at least 2 differentaugmenting/combination agents (lithium, T3, stimulants, neuroleptics,anticonvulsants, buspirone, or a second primary antidepressant) and
10. an adequate trial of electroconvulsive therapy (ECT) (>6 treatments) and anadequate trial of individual psychotherapy (>20 sessions with an experiencedpsychotherapist).
11. Able to give written informed consent.
12. Compliance to participate in the study.
13. Drug free or on stable drug regimen at least 6 weeks before study entry.

Exclusion Criteria:

1. Current or past non-affective psychotic disorder.
2. Any current clinically significant neurological disorder or medical illness affectingbrain function, other than motor tics or Gilles de la Tourette syndrome.
3. Any clinically significant abnormality on preoperative magnetic resonance imaging (MRI), any contraindications to perform a planned MRI to visualize the slMFB.
4. Any surgical contraindications to undergoing DBS like deformed or displaced or notdiscernable target region, scarring after brain disease (infarction), need forcontinuous anticoagulation that cannot be bridged in order to obtain normalcoagulation, present risks for anesthesia or any brain or scalp injury (even afterintracranial surgery).
5. Current or unstably remitted substance abuse (aside from nicotine).
6. Pregnancy, women of childbearing age not using effective contraception and breastfeeding women.
7. History of severe personality disorder.
8. Acute suicidal ideation.
9. Patients with advanced stage cardiovascular disease.
10. Patients under immunosuppressive or chemo therapy because of malignant disease.
11. Patients who had previous intracranial surgery.
12. Patients who are currently under DBS therapy or have implanted any kind of stimulatoralready.
13. Patients with aneurysm clips.
14. Patients with cochlear implants.
15. Patients with planned diathermy.
16. Persons who are in a relationship of dependence/employment with the sponsor or theinvestigator.
17. Simultaneous participation or previous participation within 30 days prior to start ofscreening in a clinical trial involving investigational medicinal product(s) orinvestigational medical device(s).