title: Two-year outcome of vagus nerve stimulation (VNS) for treatment of major depressive episodes.
abstract: BACKGROUND
  Vagus nerve stimulation (VNS) had antidepressant effects in an initial open, acute phase pilot study of 59 participants in a treatment-resistant major depressive episode (MDE). We examined the effects of adjunctive VNS over 24 months in this cohort.
  
  
  METHODS
  Adult outpatients (N = 59) with chronic or recurrent major depressive disorder or bipolar (I or II) disorder and experiencing a treatment-resistant, nonpsychotic MDE (DSM-IV criteria) received 2 years of VNS. Changes in psychotropic medications and VNS stimulus parameters were allowed only after the first 3 months. Response was defined as > or = 50% reduction from the baseline 28-item Hamilton Rating Scale for Depression (HAM-D-28) total score, and remission was defined as a HAM-D-28 score < or = 10.
  
  
  RESULTS
  Based on last observation carried forward analyses, HAM-D-28 response rates were 31% (18/59) after 3 months, 44% (26/59) after 1 year, and 42% (25/59) after 2 years of adjunctive VNS. Remission rates were 15% (9/59) at 3 months, 27% (16/59) at 1 year, and 22% (13/59) at 2 years. By 2 years, 2 deaths (unrelated to VNS) had occurred, 4 participants had withdrawn from the study, and 81% (48/59) were still receiving VNS. Longer-term VNS was generally well tolerated.
  
  
  CONCLUSIONS
  These results suggest that patients with chronic or recurrent, treatment-resistant depression may show long-term benefit when treated with VNS.
authors.affiliation: Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, Charleston, SC 29403, USA. nahasz@musc.edu
authors.forename: Ziad
authors.initials: Z
authors.lastname: Nahas
authors.forename: Lauren B
authors.initials: LB
authors.lastname: Marangell
authors.forename: Mustafa M
authors.initials: MM
authors.lastname: Husain
authors.forename: A John
authors.initials: AJ
authors.lastname: Rush
authors.forename: Harold A
authors.initials: HA
authors.lastname: Sackeim
authors.forename: Sarah H
authors.initials: SH
authors.lastname: Lisanby
authors.forename: James M
authors.initials: JM
authors.lastname: Martinez
authors.forename: Mark S
authors.initials: MS
authors.lastname: George
mesh_terms: D000553:Ambulatory Care; D002792:Cholestyramine Resin; D002908:Chronic Disease; D015331:Cohort Studies; D003131:Combined Modality Therapy; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000628:therapy*; D004599:Electric Stimulation Therapy / Q000379:methods*; D004565:Electroconvulsive Therapy; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011569:Psychiatric Status Rating Scales; D011619:Psychotropic Drugs / Q000627:therapeutic use; D012008:Recurrence; D016896:Treatment Outcome; D014630:Vagus Nerve / Q000502:physiology*
chemical_list: D011619:Psychotropic Drugs; D002792:Cholestyramine Resin