Comparison of Two tDCS Protocols for the Treatment of Major Depressive Disorder

Comparison of Two Transcranial Direct Current Stimulation (tDCS) Protocols for the Treatment of Major Depressive Disorder: a Randomized, Double-blinded, Controlled Clinical Trial.

Transcranial direct cranial stimulation (tDCS) is a novel technique based on the application of a weak electrical current over the scalp through two electrodes - the anode, which facilitates neuronal depolarization, and the cathode, which leads to neuronal hyper-polarization. Recently, several open-label and sham-controlled clinical trials applied daily tDCS sessions for the treatment of major depressive disorder (MDD). Theoretically, tDCS displays depression improvement through anodal stimulation over the left dorsolateral prefrontal, inducing excitability-enhancing effects over this area, which is hypoactive during the acute depressive episode. The present study is aimed at comparing two different tDCS protocols: (1) active anodic stimulation over left dorsolateral prefrontal cortex with cathode placed over an extra cephalic area; (2) active cathode placed over the right dorsolateral prefrontal cortex with anode placed over an extra cephalic area.

The present research protocol will evaluate clinical effects of two different tDCS protocols: (1) active anodic stimulation over left dorsolateral prefrontal cortex with cathode placed over an extra cephalic area; (2) active cathode placed over the right dorsolateral prefrontal cortex with anode placed over an extra cephalic area. Patients will be clinically evaluated with the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV) criteria for depression. Symptoms intensity will be rated according to The Hamilton Depression Scale (HAMD -17 items) - main outcome. Patients with scores higher than 16 will be included. Patients with active neurological or severe disorders (such as cancer or auto-imune disorders) will be excluded. The present study is a double-blinded, controlled, randomized trial with 30 patients with depression. The intervention protocol consist in 15 consecutive daily tDCS sessions (skipping the weekend). After meeting eligibility criteria, patients will be randomized (computer generated list) to one of the two intervention groups. We will use a direct current of 2.0 milliamperes (mA) for 30 min. The 35 cm2-rubber electrodes will be wrapped in cotton material, which should be moistened with saline as to reduce impedance. Patients will be clinically assessed at baseline and at end of 6 weeks. Main outcome will be based on HAMD-17 items at a final endpoint of 6-weeks, with secondary outcomes assessing Beck Depression Inventory (21 items) at 6 weeks. Other evaluation scales include Beck Anxiety Inventory, Hamilton Anxiety Scale and Safety and cognitive assessment will be performed with The Montreal Cognitive Assessment, adverse effects scales and clinical evaluation with a trained physician.

Transcranial Direct Current Stimulation Cathodal tDCS over F4 (right dorsolateral prefrontal cortex) Anodal tDCS over the left deltoid (extra-cephalic) n=15

Transcranial Direct Current Stimulation' Anodal tDCS over F3 (right dorsolateral prefrontal cortex) Cathodal tDCS over the right deltoid (extra-cephalic) n=15

Current Stimulation with cathodal stimulation over right dorsolateral prefrontal cortex. Anodal stimulation over left deltoid region

Inclusion Criteria: patients with age between 18-89 years, depression diagnosis according to Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-iV); HAMD scores higher than 16; accordance to inform consent Exclusion Criteria: active neurologic or severe disorder (such as cancer or auto-imune) pregnancy; need for hospitalization

Brunoni AR, Kemp AH, Shiozawa P, Cordeiro Q, Valiengo LC, Goulart AC, Coprerski B, Lotufo PA, Brunoni D, Perez AB, Fregni F, Bensenor IM. Impact of 5-HTTLPR and BDNF polymorphisms on response to sertraline versus transcranial direct current stimulation: implications for the serotonergic system. Eur Neuropsychopharmacol. 2013 Nov;23(11):1530-40. doi: 10.1016/j.euroneuro.2013.03.009. Epub 2013 Apr 21.

Brunoni AR, Benute GR, Fraguas R, Santos NO, Francisco RP, de Lucia MC, Zugaib M. The self-rated Inventory of Depressive Symptomatology for screening prenatal depression. Int J Gynaecol Obstet. 2013 Jun;121(3):243-6. doi: 10.1016/j.ijgo.2013.01.011. Epub 2013 Mar 15.

Kalu UG, Sexton CE, Loo CK, Ebmeier KP. Transcranial direct current stimulation in the treatment of major depression: a meta-analysis. Psychol Med. 2012 Sep;42(9):1791-800. doi: 10.1017/S0033291711003059. Epub 2012 Jan 12.

Brunoni AR, Valiengo L, Baccaro A, Zanao TA, de Oliveira JF, Goulart A, Boggio PS, Lotufo PA, Bensenor IM, Fregni F. The sertraline vs. electrical current therapy for treating depression clinical study: results from a factorial, randomized, controlled trial. JAMA Psychiatry. 2013 Apr;70(4):383-91. doi: 10.1001/2013.jamapsychiatry.32.

Brunoni AR, Ferrucci R, Fregni F, Boggio PS, Priori A. Transcranial direct current stimulation for the treatment of major depressive disorder: a summary of preclinical, clinical and translational findings. Prog Neuropsychopharmacol Biol Psychiatry. 2012 Oct 1;39(1):9-16. doi: 10.1016/j.pnpbp.2012.05.016. Epub 2012 May 28.

Brunoni AR, Ferrucci R, Bortolomasi M, Vergari M, Tadini L, Boggio PS, Giacopuzzi M, Barbieri S, Priori A. Transcranial direct current stimulation (tDCS) in unipolar vs. bipolar depressive disorder. Prog Neuropsychopharmacol Biol Psychiatry. 2011 Jan 15;35(1):96-101. doi: 10.1016/j.pnpbp.2010.09.010. Epub 2010 Sep 18.