title: Subcallosal cingulate gyrus deep brain stimulation for treatment-resistant depression.
abstract: BACKGROUND
  A preliminary report in six patients suggested that deep brain stimulation (DBS) of the subcallosal cingulate gyrus (SCG) may provide benefit in treatment-resistant depression (TRD). We now report the results of these and an additional 14 patients with extended follow-up.
  
  
  METHODS
  Twenty patients with TRD underwent serial assessments before and after SCG DBS. We determined the percentage of patients who achieved a response (50% or greater reduction in the 17-item Hamilton Rating Scale for Depression [HRSD-17]) or remission (scores of 7 or less) after surgery. We also examined changes in brain metabolism associated with DBS, using positron emission tomography.
  
  
  RESULTS
  There were both early and progressive benefits to DBS. One month after surgery, 35% of patients met criteria for response with 10% of patients in remission. Six months after surgery, 60% of patients were responders and 35% met criteria for remission, benefits that were largely maintained at 12 months. Deep brain stimulation therapy was associated with specific changes in the metabolic activity localized to cortical and limbic circuits implicated in the pathogenesis of depression. The number of serious adverse effects was small with no patient experiencing permanent deficits.
  
  
  CONCLUSIONS
  This study suggests that DBS is relatively safe and provides significant improvement in patients with TRD. Subcallosal cingulate gyrus DBS likely acts by modulating brain networks whose dysfunction leads to depression. The procedure is well tolerated and benefits are sustained for at least 1 year. A careful double-blind appraisal is required before the procedure can be recommended for use on a wider scale.
authors.affiliation: Division of Neurosurgery, University of Toronto, Toronto, Canada. lozano@uhnres.utoronto.ca
authors.forename: Andres M
authors.initials: AM
authors.lastname: Lozano
authors.forename: Helen S
authors.initials: HS
authors.lastname: Mayberg
authors.forename: Peter
authors.initials: P
authors.lastname: Giacobbe
authors.forename: Clement
authors.initials: C
authors.lastname: Hamani
authors.forename: R Cameron
authors.initials: RC
authors.lastname: Craddock
authors.forename: Sydney H
authors.initials: SH
authors.lastname: Kennedy
mesh_terms: D002540:Cerebral Cortex / Q000378:metabolism / Q000503:physiopathology; D003337:Corpus Callosum; D046690:Deep Brain Stimulation / Q000379:methods*; D003865:Major Depressive Disorder / Q000378:metabolism / Q000503:physiopathology* / Q000601:surgery*; D004351:Drug Resistance; D005260:Female; D005947:Glucose / Q000378:metabolism; D006179:Gyrus Cinguli / Q000033:anatomy & histology / Q000378:metabolism / Q000601:surgery*; D006801:Humans; D008032:Limbic System / Q000378:metabolism / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D049268:Positron-Emission Tomography; D012720:Severity of Illness Index; D013238:Stereotaxic Techniques; D011795:Surveys and Questionnaires
chemical_list: D005947:Glucose