title: Deep brain stimulation for treatment-resistant depression: follow-up after 3 to 6 years.
abstract: OBJECTIVE
  A prevalence of at least 30% for treatment-resistant depression has prompted the investigation of alternative treatment strategies. Deep brain stimulation (DBS) is a promising targeted approach involving the bilateral placement of electrodes at specific neuroanatomical sites. Given the invasive and experimental nature of DBS for treatment-resistant depression, it is important to obtain both short-term and long-term effectiveness and safety data. This report represents an extended follow-up of 20 patients with treatment-resistant depression who received DBS to the subcallosal cingulate gyrus (Brodmann's area 25).
  
  
  METHODS
  After an initial 12-month study of DBS, patients were seen annually and at a last follow-up visit to assess depression severity, functional outcomes, and adverse events.
  
  
  RESULTS
  The average response rates 1, 2, and 3 years after DBS implantation were 62.5%, 46.2%, and 75%, respectively. At the last follow-up visit (range=3-6 years), the average response rate was 64.3%. Functional impairment in the areas of physical health and social functioning progressively improved up to the last follow-up visit. No significant adverse events were reported during this follow-up, although two patients died by suicide during depressive relapses.
  
  
  CONCLUSIONS
  These data suggest that in the long term, DBS remains a safe and effective treatment for treatment-resistant depression. Additional trials with larger samples are needed to confirm these findings.
authors.affiliation: Department of Psychiatry, Division of Neurosurgery, University Health Network, Toronto, Canada. sidney.kennedy@uhn.on.ca
authors.forename: Sidney H
authors.initials: SH
authors.lastname: Kennedy
authors.forename: Peter
authors.initials: P
authors.lastname: Giacobbe
authors.forename: Sakina J
authors.initials: SJ
authors.lastname: Rizvi
authors.forename: Franca M
authors.initials: FM
authors.lastname: Placenza
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Nishikawa
authors.forename: Helen S
authors.initials: HS
authors.lastname: Mayberg
authors.forename: Andres M
authors.initials: AM
authors.lastname: Lozano
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D046690:Deep Brain Stimulation / Q000009:adverse effects; D003865:Major Depressive Disorder / Q000628:therapy*; D005500:Follow-Up Studies; D006179:Gyrus Cinguli; D006801:Humans; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D013405:Suicide / Q000523:psychology; D013997:Time Factors; D017211:Treatment Failure