Update on Deep Brain Stimulation for Treatment-Resistant Depression

Major depression is one of the leading causes of disability worldwide since it is often accompanied by high rates of resistance to treatment. Up to 40% of patients do not remit after two adequate pharmacological tryouts (as indicated by STAR*D study). Poor efficacy of drugs for treatment-resistant depression (TRD) has prompted investigation of alternative treatment strategies. Deep Brain Stimulation (DBS) involves the high-frequency electrical stimulation of stereotaxically implanted electrodes in certain brain regions. Various target areas have been examined for DBS to modulate cortico-limbic circuits, including the anterior limb in the internal capsule, the ventral capsule / ventral striatum (VC/VS), the nucleus accumbens (NAc), and the subgenual cingulate gyrus (SCG, Cg25). DBS for treatment-resistant depression is showing promising results in the few studies published to date, and could potentially open new therapeutic opportunities as an effective long-term treatment strategy with low adverse effects for such a chronic, refractory population.