Two-year outcome of vagus nerve stimulation (VNS) for treatment of major depressive episodes.
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 By 2 years, 2 deaths (unrelated to VNS) had occurred, 4 participants had withdrawn from the study, and 81% (48/59) were still receiving VNS.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.
Nahas
Ziad
Z
Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, Charleston, SC 29403, USA. nahasz@musc.edu
Marangell
Lauren B
LB
Husain
Mustafa M
MM
Rush
A John
AJ
Sackeim
Harold A
HA
Lisanby
Sarah H
SH
Martinez
James M
JM
George
Mark S
MS
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*
D011619:Psychotropic Drugs; D002792:Cholestyramine Resin