Psychiatr Clin North Am 2000 Dec;23(4):757-83 Vagus nerve stimulation. A potential therapy for resistant depression? George MS, Sackeim HA, Marangell LB, Husain MM, Nahas Z, Lisanby SH, Ballenger JC, Rush AJ. Department of Psychiatry, Medical University of South Carolina, USA. VNS builds on a long history of investigating the relationship of autonomic signals to limbic and cortical function and is one of the newest methods to physically alter brain function. VNS is a clinically useful anticonvulsant therapy in treatment resistant patients with epilepsy, and pilot data suggest that it has potential as an antidepressant therapy. The known anatomic projections of the vagus nerve suggest that VNS also might have other neuropsychiatric applications. Additional research is needed to clarify the mechanisms of action of VNS and the potential clinical utility of this intriguing new somatic portal into the CNS.
Biol Psychiatry 2000 Feb 15;47(4):276-86 Vagus nerve stimulation (VNS) for treatment-resistant depressions: a multicenter study. Rush AJ, George MS, Sackeim HA, Marangell LB, Husain MM, Giller C, Nahas Z, Haines S, Simpson RK Jr, Goodman R. Departments of Psychiatry and Neurosurgery, University of Texas Southwestern Medical Center, Dallas 75235-9086, USA. BACKGROUND: Vagus Nerve Stimulation (VNS) delivered by the NeuroCybernetic Prosthesis (NCP) System was examined for its potential antidepressant effects. METHODS: Adult outpatients (n = 30) with nonpsychotic, treatment-resistant major depressive (n = 21) or bipolar I (n = 4) or II (n = 5; depressed phase) disorders who had failed at least two robust medication trials in the current major depressive episode (MDE) while on stable medication regimens completed a baseline period followed by NCP System implantation. A 2-week, single-blind recovery period (no stimulation) was followed by 10 weeks of VNS. RESULTS: In the current MDE (median length = 4.7 years), patients had not adequately responded to two (n = 9), three (n = 2), four (n = 6), or five or more (n = 13) robust antidepressant medication trials or electroconvulsive therapy (n = 17). Baseline 28-item Hamilton Depression Rating Scale (HDRS(28)) scores averaged 38.0. Response rates (> or =50% reduction in baseline scores) were 40% for both the HDRS(28) and the Clinical Global Impressions-Improvement index (score of 1 or 2) and 50% for the Montgomery-Asberg Depression Rating Scale. Symptomatic responses (accompanied by substantial functional improvement) have been largely sustained during long-term follow-up to date. CONCLUSIONS: These open trial results suggest that VNS has antidepressant effects in treatment-resistant depressions.