Electroconvulsive therapy prescribers, practitioners and many patients will be aware of an emerging clinical evidence base for non-ECT brain stimulation treatments. Although the previous edition of The ECT Handbook made no mention of brain stimulation treatments, a review of the status of the three most studied therapies is now relevant. These therapies are:
• repetitive transcranial magnetic stimulation
• vagus nerve stimulation
• deep brain stimulation.
In this chapter, we consider the use of these therapies in the management of depression and how they might relate to the ECT treatment pathway.
Repetitive transcranial magnetic stimulation (rTMS)
Repetitive transcranial magnetic stimulation is a non-invasive technique causing modification of brain activity by focal stimulation of the superficial layers of the cerebral cortex using a train of magnetic pulses via an external wire coil. The impetus for studies of rTMS in psychiatry has arisen from the need for a viable alternative to ECT with a lower burden of adverse effects and greater patient acceptability. A substantial literature, including several systematic reviews and meta-analyses, now exists on the use of rTMS in the management of depression. In 2008 the US Food and Drug Administration approved a TMS system ‘for the treatment of Major Depressive Disorder in adult patients who have failed to achieve satisfactory improvement from one prior antidepressant medication at or above the minimal effective dose and duration in the current episode’.
However, NICE published a technology appraisal in 2007, restating the core recommendations in the 2010 depression guideline update, which is consistent with the absence of convincing evidence of superior efficacy for rTMS over sham treatment and with the paucity of efficacy data extending beyond 4–6 weeks of treatment. The status of the technique is summarised as follows:
‘Current evidence suggests that there are no major safety concerns associated with transcranial magnetic stimulation (TMS) for severe depression. There is uncertainty about the procedure's clinical efficacy, which may depend on higher intensity, greater frequency, bilateral application and/or longer treatment durations than have appeared in the evidence to date. TMS should therefore be performed only in research studies designed to investigate these factors.’ (National Institute for Health and Clinical Excellence, 2007)
In our opinion, on the basis of current evidence, rTMS remains an interesting but experimental therapy which should not be considered a viable alternative to treatment with ECT.