There has never been a more exciting time in the field of intervention development in Psychiatry. Recently, the Food and Drug Administration approved repetitive transcranial magnetic stimulation (rTMS) for the treatment of certain forms of major depressive disorder (MDD). Repetitive transcranial magnetic stimulation joins electroconvulsive therapy (ECT) as an Food and Drug Administration-approved clinical treatment for depression, and together they comprise a family of neuromodulation interventions that offer physicians an expanded array of therapeutic options. Unlike ECT, rTMS can also be used in healthy volunteers as a probe to study brain function because it is noninvasive. This special issue of the Journal of ECT, which is dedicated to the science of ECT and related treatments, focuses on rTMS to provide information regarding its utility as both a neuroscientific probe and a neurotherapeutic intervention. As a neuroscientific probe, rTMS can be used to explore neural physiology, connectivity, and transmission to further understanding of normal brain function and of neuropsychiatric diseases. As a neurotherapeutic intervention, rTMS can be used to modulate neural functioning to treat neuropsychiatric disease states, such as MDD.
In this issue, we begin with a manuscript by Kozel et al who combined rTMS with diffusion tenser imaging, a sophisticated and sensitive neuroimaging tool to explore the mechanisms of antidepressant action and safety of rTMS. This is complemented by work from George et al who demonstrate the safety and tolerability of daily rTMS administered over the dorsolateral prefrontal cortex for the treatment of severe depression.
In addition to being used as a treatment of depression, rTMS has been applied as a noninvasive neuromodulation probe and intervention for other neuropsychiatric and neurological disorders. Stanford et al examine the potential utility of rTMS to decrease negative symptoms of schizophrenia, and the use of deep TMS was found to improve social functioning in a patient with autism spectrum disorder. With regard to neurologic illnesses, Sampson et al and Fitzgerald et al found rTMS to be beneficial for the treatment of refractory neuropathic pain and depression secondary to traumatic brain injury, respectively.
We are at a point of further using TMS to advance our understanding and treatment of neuropsychiatric disease. However, many questions remain, including what type of rTMS to use (eg, single pulse, paired pulse, or repetitive pulses), how to use it (eg, daily or weekly), which neuropsychiatric diseases will respond and remit (eg, depression, schizophrenia, anxiety disorders, and other conditions). To date, the largest body of evidence regarding the therapeutic use of TMS is for the treatment of severe depression. Two large-scale clinical controlled trials, one sponsored by industry and the other by the National Institutes of Health, found rTMS (applied over the dorsolateral prefrontal cortex) to have significant antidepressant effects, however, with modest response and remission rates. Repetitive transcranial magnetic stimulation is not a panacea for depression, nor is it a replacement for other forms of neurotherapeutic interventions, particularly ECT. This is highlighted in a study by Hansen et al who found that ECT, compared to rTMS, had a higher rate of remission, and in an editorial by Dr Max Fink, one of the most respected researchers in the field of ECT. We appreciate his comments and agree when he notes that "TMS is not a replacement for ECT-In our opinion it's a complimentary brain stimulation therapy for MDD."
Neurostimulation represents an evolving science in the 21st century. Advances in this field will require further careful study of these techniques and will be facilitated by critical examination of the literature. To this end, we present this special issue on rTMS to encourage future investigations in its application as both a neuroscientific probe and a neurotherapeutic intervention. Focusing on the data rather than on the former dogma that a seizure is always necessary for therapeutic response will enable us to take an evidence-based approach to this growing field. Our patients deserve nothing less than everything that medical science has to offer that has the potential to have a positive benefit in their lives.
The authors thank Dr Shawn M. McClintock and Dr Syed H. Husaini for their assistance in the preparation of this editorial.