Somatic therapies for treatment-resistant depression: new neurotherapeutic interventions

Abstract

This brief review provides an overview of neurotherapeutic interventions for major depression that are available currently or are being studied in clinical trials. The growing utility of surgical and device-related treatments for psychiatric conditions may represent a sea change in the field of psychiatry comparable to that seen in other clinical disciplines. For example, for many years the overwhelming majority of cardiac conditions were treated with medications and behavioral interventions. With the advent of cardiac surgical procedures such as ablation and cardiac bypass surgery and the use of devices such as cardiac stents and pacemakers, the ability to treat cardiac disease has improved dramatically. The hope is that the use of neurotherapeutic interventions will lead to a similar improvement in the treatment of psychiatric illness. The future of neurotherpeutic interventions in psychiatry may include the use of neuroimaging technology to predict with patients may respond to which procedures or to guide the placement of DBS electrodes on an individual basis. DBS electrodes also could be placed in multiple brain regions. Clinical trials of cortical stimulation using surgically implanted electrodes on the brain surface are underway. These cortical-surface electrodes could provide cortical stimulation comparable to that induced by rTMS at the same location, obviating the need for visits to a physician for rTMS treatments and providing cortical stimulation of a greater magnitude and for an extended duration. Also, one can foresee surgical interventions in which neurotransmitter release is potentiated either by stimulating appropriate nuclei in the brain or by releasing neurotransmitters or neurotransmitter precursors into target brain regions using cannulae or an implanted device. Neurotrophic factors also could be introduced into target brain regions using analogous techniques. Although the future of neurotherapeutic interventions in psychiatry is hard to predict, it is clear that these treatments will have a growing role in the field.