The Use of Repetitive Transcranial Magnetic Stimulation and Vagal Nerve Stimulation in the Treatment of Depression

Paul B. Fitzgerald; Zafiris J. Daskalakis


Curr Opin Psychiatry. 2008;21(1):25-29. 

In This Article

Abstract and Introduction

Purpose of review: Patients with depressive disorders often fail to respond to standard antidepressant medications and have few available treatment alternatives. Repetitive transcranial magnetic stimulation and vagal nerve stimulation have been developed and investigated over the last 10 years as potential treatment options for this and other psychiatric conditions. The aim of this paper is to review recent therapeutic trials of these techniques.
Recent findings: Recent studies appear to have confirmed that standard left-sided repetitive transcranial magnetic stimulation has antidepressant efficacy, but that the degree of clinical effect may be somewhat limited. Promising data are emerging suggesting that other approaches, including right unilateral repetitive transcranial magnetic stimulation and sequential bilateral stimulation, may have equal or potentially greater effects. The evidence for the effectiveness of vagal nerve stimulation remains restricted to the primary company-sponsored trials. Although limited, these data suggest that valuable treatment effects may develop over time.
Summary: Further repetitive transcranial magnetic stimulation research should actively investigate novel stimulation approaches before high-frequency left-sided stimulation is accepted as the standard approach. Given the invasive nature of vagal nerve stimulation and potential side effects, further research is urgently required. This should include the development of predictors of clinical response and definition of stimulation parameters with enhanced efficacy.

Recent years have seen a marked escalation of interest in the use of invasive and noninvasive forms of brain stimulation for the treatment of mood disorders, especially for patients with treatment-resistant depression. Research into the use of transcranial magnetic stimulation (TMS) first commenced in earnest in the mid-1990s and since then a considerable number of randomized controlled trials have been published. The majority of trials published, however, have included relatively small samples of patients and treatment has been relatively restricted in duration and dose. Recently, trials have begun to include larger numbers of patients and have provided treatment for longer periods of time. As such there is a growing evidence base from which to judge the potential value of this technique. Vagal nerve stimulation (VNS) is supported by a more restricted evidence base, but has moved fairly rapidly into clinical practice in some countries. Therefore, there is considerable clinical interest in both of these techniques, and as such the focus of this article is to review recent studies that relate to their efficacy, safety and mechanism of action.


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