A randomized, double-blind clinical trial on the efficacy of cortical direct current stimulation for the treatment of major depression

Paulo S Boggio,Felipe Fregni,Martin L Myczkowski,Sergio P Rigonatti,Michael A Nitsche,Rafael B Ribeiro,Alvaro Pascual-Leone

doi:10.1017/s1461145707007833

Abstract

Preliminary findings suggest that transcranial direct current stimulation (tDCS) can have antidepressant effects. We sought to test this further in a parallel-group, double-blind clinical trial with 40 patients with major depression, medication-free randomized into three groups of treatment: anodal tDCS of the left dorsolateral prefrontal cortex (active group - 'DLPFC'); anodal tDCS of the occipital cortex (active control group - 'occipital') and sham tDCS (placebo control group - 'sham'). tDCS was applied for 10 sessions during a 2-wk period. Mood was evaluated by a blinded rater using the Hamilton Depression Rating Scale (HDRS) and Beck Depression Inventory (BDI). The treatment was well tolerated with minimal side-effects that were distributed equally across all treatment groups. We found significantly larger reductions in depression scores after DLPFC tDCS [HDRS reduction of 40.4% (+/-25.8%)] compared to occipital [HDRS reduction of 21.3% (+/-12.9%)] and sham tDCS [HDRS reduction of 10.4% (+/-36.6%)]. The beneficial effects of tDCS in the DLPFC group persisted for 1 month after the end of treatment. Our findings support further investigation on the effects of this novel potential therapeutic approach - tDCS - for the treatment of major depression.

Highlights

Different neurostimulation techniques are considered for treatment of depression : electroconvulsive therapy (UK ECT Review Group, 2003), vagus nerve stimulation (Sackeim et al, 2001), deep brain stimulation (Mayberg et al, 2005), repetitive transcranial magnetic stimulation (Gershon et al, 2003; Herrmann and Ebmeier, 2006; Martin et al, 2003); or magnetic seizure therapy (Kosel et al, 2003)
The results of this study show that cortical stimulation with transcranial direct current stimulation (tDCS) is associated with a significant reduction in depression scores that is specific to the site of stimulation and lasts for at least 30 d after the end of treatment
TDCS might offer some advantages compared with repetitive transcranial magnetic stimulation (rTMS) as a relatively safe, non-expensive and easyto-administer technique of non-invasive brain stimulation

Summary

Introduction

Different neurostimulation techniques are considered for treatment of depression : electroconvulsive therapy (UK ECT Review Group, 2003), vagus nerve stimulation (Sackeim et al, 2001), deep brain stimulation (Mayberg et al, 2005), repetitive transcranial magnetic stimulation (rTMS) (Gershon et al, 2003; Herrmann and Ebmeier, 2006; Martin et al, 2003); or magnetic seizure therapy (Kosel et al, 2003). Despite mixed findings in the past (Lolas, 1977), recent preliminary data suggest that transcranial direct current stimulation (tDCS), another non-invasive method of brain stimulation, might be useful in depression if appropriate currents, electrode sizes, and montages are employed (Fregni et al, 2006b). In tDCS, low-amplitude direct currents are injected into the brain via scalp electrodes (Nitsche and Paulus, 2000). As shown by a recent modelling study, a significant amount of electric current can reach the brain using appropriately large electrodes and suitable placements (Miranda et al, 2006). Recent studies with up-to-date parameters of stimulation have shown that tDCS is a powerful neuromodulation technique (Nitsche et al, 2003b). Responsivity of the targeted brain regions to afferent input or efferent demand is modified

Methods

Results

Conclusion