SEARCH

SEARCH BY CITATION

Keywords:

  • major depressive disorder;
  • transcranial direct current stimulation;
  • follow-up study, clinical trial;
  • Kaplan–Meier analysis;
  • refractory depression

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.