SYMPOSIA

Abstracts of the Invited Speakers
of patients with medication-refractory unipolar depression who have failed one good (but not more than one) pharmacological trial.
Key words: Transcranial magnetic stimulation, depression, rTMS
References:
1. Barker AT, Jalinous R, Freeston IL. Non-invasive magnetic stimulation of human motor cortex. Lancet1985;1(8437):1106-7.
2. Nivoli AM, Colom F, Murru A, Pacchiarotti I, Castro-Loli P, González-Pinto A, et al. New treatment guidelines for acute bipolar depression: A systematic review. J
Affect Disord 2011; 129(1-3):14-26.
3. Fitzgerald PB, Hoy K, McQueen S, Maller JJ, Herring S, Segrave R, et al. A Randomized Trial of rTMS Targeted with MRI Based Neuro-Navigation in Treatment-
Resistant Depression. Neuropsychopharmacology 2009; 34(5):1255-62.
Bulletin of Clinical Psychopharmacology 2011;21(Suppl. 2):S59-60
Vagus Nerve Stimulation (VNS) in depression treatment
Şadiye Visal Buturak
Department of Psychiatry, Kırıkkale University, Faculty of Medicine, Kırıkkale, Turkey
E-mail: visalbuturak@hotmail.com
Major Depressive Disorder (MDD) is a prevalent, chronic, recurrent and disabling disorder and it is predicted that MDD will be the second most common
cause of incapacitating disease in 2020 (1). Although a broad range of effective treatments is available, a considerable proportion of patients do not
respond adequately (2). Patients who have already experienced recurrent depressive episodes often relapse and do not achieve full remission despite
treatment with conventional therapies (3). A need for the development of alternative treatments for treatment resistant depression (TRD) that are
effective, have fewer side-effects or have longer-lasting antidepressant effects has been identified. Vagus nerve stimulation (VNS) therapy is a type of
treatment where a small electrical pulse is administered through an implanted neurostimulator to a bipolar lead attached to the left vagus nerve (4).
VNS was approved by the US Food and Drug Administration in 2005 for the adjunctive long-term treatment of chronic or recurrent depression for
patients 18 years or older who are experiencing a major depressive episode (MDE) and have not had an adequate response to 4 or more adequate
antidepressant treatments. The mechanism of action of VNS is not fully understood although emerging data suggest that VNS therapy modulates the
function of neural structures implicated in depression and also influences monoaminergic neurotransmission (5). In a randomized sham-controlled
trial, VNS only showed a response rate of 15.2% compared to 10% with sham treatment (p=0.251) during a 10 week trial (6). But most of the open-label
studies about the short and long-term efficacy of the VNS in patients with TRD showed significant reductions in response and remission rates. Rush et
al. examined the effect of VNS in adult outpatients with nonpsychotic, treatment-resistant major depressive or bipolar I or II (depressed phase) disorders.
Response rates were 40% for the Hamilton Depression Rating Scale (HDRS) (7). In an open pilot study of VNS in outpatients with treatment-resistant
MDEs the response rate was 30.5% for the primary HDRS (28) measure, after 10 weeks of VNS (p =.0057) (8). George et al. compared data from the 205
patients who completed the 12-month naturalistic study that was done by Rush et al. (9) with a matched control group of 124 patients with TRD who
received only treatment as usual (TAU). Response rates according to the HDRS (24) at 12 months were 27% for VNS+TAU and 13% for TAU (p