Comparison of Two tDCS Protocols for the Treatment of Major Depressive Disorder
Condition: MAjor Depressive Disorder
MeSH terms: Depressive Disorder; Depression; Depressive Disorder, Major
Study type: Interventional

Summary: 
      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.
    

Detailed description: 
      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.
    

Intervention name(s): Transcranial Direct Current Stimulation
Intervention type(s): Device
Intervention description(s): Current Stimulation with cathodal stimulation over right dorsolateral prefrontal cortex. Anodal stimulation over left deltoid region
Other intervention name(s): tDCS; Brain polarization; Brain stimulation
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: tDCS; Brain stimulation; depressive disorder