Novel physical treatments for major depression: vagus nerve stimulation, transcranial magnetic stimulation and magnetic seizure therapy

Purpose of review Transcranial magnetic stimulation, vagus nerve stimulation and magnetic seizure therapy are currently studied as potential treatment options for affective disorders. We review the recent developments (mainly since July 2002) in their clinical applications and new contributions to the basic understanding of their mechanisms of action. Recent findings Transcranial magnetic stimulation has clear antidepressant properties, as supported by several recently published metaanalyses. It is not yet clear, however, whether these effects are clinically meaningful and, if so, in which population of depressed people. To assess these questions, large controlled and comparative (against pharmaco- and electroconvulsive therapy) multicenter studies are needed but are not available to date. In addition, optimal treatment parameters (place of stimulation, stimulation parameters, number of sessions etc.) have to be defined. Since July 2002, no new data concerning the efficacy of vagus nerve stimulation in depression have been published. Published and unpublished results indicate that the best antidepressant effects of this treatment can be expected at 12 months after the start of stimulation. A recently published case report on magnetic seizure therapy describes the first successful antidepressant treatment of a treatment refractory patient. The application of this methodology is still experimental. Summary If these novel physical treatments will have a place as treatment modalities of affective disorders and how they exert their antidepressant effects is not yet known. Many studies are being conducted addressing these basic questions and they may help to elucidate crucial issues of the neurobiology of depression itself.