Transcranial Direct Current Stimulation (tDCS) As Treatment for Major Depression

Overview

Major depressive disorder (MDD) is a common, recurrent, and frequent chronic disorder. Treatment is often challenging; an estimated 20-40% of patients do not benefit sufficiently from existing antidepressant interventions including trials of medication and psychotherapy. A 15-25% of patients manifest a chronic, treatment-resistant course of illness, resulting in a need for additional treatment options. Brain stimulation techniques are considered as a promising therapeutic approach in affective disorders like MDD. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method that has been largely investigated in experimental neurosciences and tDCS of the prefrontal cortex (PFC) has been proposed as novel treatment in MDD. In the largest 2x2 factorial randomized controlled trial in MDD to date, Brunoni et al. (2013) have shown that tDCS combined with an Selective Serotonin Reuptake Inhibitor (SSRI; sertraline) resulted in an antidepressant efficacy superior to placebo treatment, tDCS alone and sertraline alone. The purpose of this study is to explore the sustained efficacy and tolerability of repeated tDCS for the treatment of MDD. It is hypothesized that prefrontal tDCS in combination with an SSRI will provoke an antidepressant effect while antidepressant medication alone (sham tDCS) did not. This will be measured by the change from baseline in the Montgomery Åsberg Depression Rating Scale (MADRS) scores after 6 weeks of treatment. In this randomized, placebo-controlled multicenter trial (5 centers involved) patients with a diagnosis of MDD receive a 6-weeks treatment with prefrontal tDCS (anode over electrode position F3, cathode over F4, 5 sessions/week for 4 weeks followed by 2 sessions/week for 2 weeks, 24 treatments in sum, 30min/day, 2mA intensity) or sham tDCS (frequency and duration correspondent active tDCS, ramp in and ramp out periods only without intermittent stimulation), as adjunctive treatment with a SSRI. Follow-up per patient is 3 and 6 months after the last tDCS treatment session. Before, during and after the treatment period different assessment scales will be conducted to record neuropsychological features and the course of the individual symptomatology.