Background: Transcranial direct current stimulation (tDCS) is a promising nonpharmacological therapy for major depression. In the Sertraline versus Electrical Current Therapy for Treating Depression Clinical Trial (SELECT-TDCS) trial, phase-I (Brunoni et al., JAMA Psychiatry, 2013) we found that tDCS is effective for the acute episode. Here, we describe tDCS effects during phases II (crossover) and III (follow-up) of this trial (NCTs: 01149889 and 01149213).
Methods: Phase II (n = 25) was the open-label, crossover phase in which phase-I nonresponders who had received sham-tDCS received a 10-day course of active-tDCS. In phase-III (n = 42), all active-tDCS responders (>50% Montgomery-Asberg Depression Rating Scale (MADRS) improvement or MADRS ≤ 12) were enrolled to a 24-week, follow-up phase in which a maximum of nine tDCS sessions were performed-every other week for 3 months and, thereafter, once a month for the subsequent 3 months-sessions would be interrupted earlier whether the subject relapsed. TDCS was applied at 2 mA/30 min, with the anode over the left and the cathode over the right dorsolateral prefrontal cortex. Relapse was the outcome measure.
Results: In phase-II, 52% of completers responded to tDCS. In phase-III, the mean response duration was 11.7 weeks. The survival rate per Kaplan-Meier analysis was 47%. Patients with treatment-resistant depression presented a much lower 24-week survival rate as compared to nonrefractory patients (10% vs. 77%, OR = 5.52; P < .01). Antidepressant use (sertraline 50 mg/day, eight patients) was not a predictor of relapse. TDCS was well tolerated and with few side effects.
Conclusion: Continuation tDCS protocols should be optimized as to prevent relapse among tDCS responders, particularly for patients with baseline treatment-resistant depression.
Keywords: Kaplan-Meier analysis; follow-up study, clinical trial; major depressive disorder; refractory depression; transcranial direct current stimulation.
© 2013 Wiley Periodicals, Inc.