Transcranial Direct Current Stimulation as an Augmenting Intervention for Major Depression

Transcranial Direct Current Stimulation (tDCS) as an Augmenting Intervention for Treatment-Resistant Major Depression: A Randomized, Double-Blind and Sham-Controlled Trial

Transcranial direct current stimulation (tDCS) is a noninvasive method to activate or de-activate neurons in superficial regions of the brain through the induction of weak electric currents in the brain tissue delivered by two scalp electrodes. Initial studies have shown tDCS to be effective for treating major depressive disorder (MDD), although there are negative trials in the specialized literature. One reason for these discrepant results might be that the duration of tDCS treatment in clinical trials to date (up to 2 weeks) is still insufficient to produce consistent clinical improvements. Thus, we intend to assess, in a sample of outpatients with MDD, whether a 3-week adjunctive course of active tDCS over the left dorsolateral prefrontal cortex is associated with a significant clinical improvement when compared to sham tDCS. The investigators hypothesize that subjects receiving active tDCS will present with significantly higher response and remission rates at weeks 3.

The tDCS stimulator will be turned on for 30 seconds only, after which it will be gradually decreased and then turned off for the remainder of the 20-minute daily sessions for 15 days (Monday to Friday on three consecutive weeks).

Response to treatment is defined as a ≥ 50% reduction in pretreatment symptoms severity at as measured by the mean QIDS-C score. Remission is defined as a QIDS-C score ≤ 5

Response to treatment is defined as a ≥ 50% reduction in the scores of the HAM-D21. Remission is defined as a HAM-D21 score ≤ 8

Response is defined as a ≥ 50% reduction in the scores of the QIDS-SR. Remission is defined as a QIDS-SR score ≤ 5

Inclusion Criteria: Presence of a current major depressive disorder (according to the Diagnostic and Statistical Manual, Fourth Edition, Text Revision [DSM-IV-TR]) Baseline score ≥ 13 on the QIDS-C Stable medication regimen (> 4 weeks) Exclusion Criteria: Psychotic features in the current episode Lifetime history of psychotic disorders and/or bipolar I or II disorders Substance or alcohol abuse/dependence in the past 6 months Lifetime history of a major neurological disease (e.g., Parkinson's, stroke) Uncontrolled medical disease (e.g., cardiovascular, renal) Pregnancy and/or lactation Presence of a specific contraindication for tDCS (e.g., personal history of epilepsy, metallic head implant, cardiac pacemaker)

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Murphy DN, Boggio P, Fregni F. Transcranial direct current stimulation as a therapeutic tool for the treatment of major depression: insights from past and recent clinical studies. Curr Opin Psychiatry. 2009 May;22(3):306-11. doi: 10.1097/YCO.0b013e32832a133f.

Arul-Anandam AP, Loo C. Transcranial direct current stimulation: a new tool for the treatment of depression? J Affect Disord. 2009 Oct;117(3):137-45. doi: 10.1016/j.jad.2009.01.016. Epub 2009 Feb 7.

Boggio PS, Rigonatti SP, Ribeiro RB, Myczkowski ML, Nitsche MA, Pascual-Leone A, Fregni F. A randomized, double-blind clinical trial on the efficacy of cortical direct current stimulation for the treatment of major depression. Int J Neuropsychopharmacol. 2008 Mar;11(2):249-54. doi: 10.1017/S1461145707007833. Epub 2007 Jun 11.