Clinical and Electrophysiological Outcomes of tDCS in Patients With Treatment Resistant OCD
Condition: Obsessive-Compulsive Disorder
MeSH terms: Compulsive Personality Disorder; Obsessive-Compulsive Disorder
Study type: Interventional

Summary: 
      The aim of this study is to analyze the effectiveness of three different montages of
      transcranial direct current stimulation (tDCS) in treating treatment-resistant OCD.
    

Detailed description: 
      Obsessive-compulsive disorder (OCD) typically starts between childhood and early adulthood
      and is characterized by the presence of obsessions and/or compulsions and a typically chronic
      clinical course. Around one-third of OCD patients fail to benefit significantly from
      first-line treatment, e.g., serotonin reuptake inhibitors (SRIs) or cognitive behavioral
      therapy (CBT). Combining, augmenting, and switching strategies as second-line treatments also
      fail to bring much benefit to these patients. When the first-line and second-line treatments
      fail, alternative treatments (e.g., non-invasive brain stimulation techniques) should be
      considered. A proposed pathophysiology of OCD is the dysfunction of
      cortico-striato-thalamo-cortical circuitry including the medial prefrontal cortex [i.e.,
      supplementary motor area (SMA) and anterior cingulate cortex (ACC)], the dorso-lateral
      prefrontal cortex (DLPFC), the orbitofrontal cortex (OFC), and the basal ganglia. Among novel
      therapeutic options of non-invasive brain stimulation, transcranial direct current
      stimulation (tDCS) has shown positive results (e.g., cathodal tDCS over the pre-SMA, tDCS
      with the cathode over the left OFC and the anode over the right cerebellum, and tDCS with
      anode over Pre-SMA and cathode over right supra-orbital area) in treatment-resistant OCD.
      However, there is unclear evidence regarding the best tDCS montage for treatment-resistant
      OCD. This study investigates the effects of three different tDCS montages in reducing the
      symptoms of patients with treatment-resistant OCD. Eligible participants with
      treatment-resistant OCD will be allocated randomly into three groups of different tDCS
      montages [1. The right cerebellum (anode) and the left OFC (cathode) tDCS; 2. The bilateral
      pre-SMA (cathode) and right deltoid (reference) tDCS; 3. The left OFC (cathode 1), bilateral
      pre-SMA (cathode 2), and right deltoid (reference) tDCS]. Patients will receive twice-daily
      sessions separated by at least 1 h for 10 consecutive weekdays. One session of tDCS consists
      in delivering a direct current of 2 mA during 20 min. The primary outcome is the difference
      in the change of the score of the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) between
      three different montages of tDCS. Electrical activity of the brain as measured by EEG,
      autonomic function as measured by heart rate variability, and cognitive functioning as
      secondary outcomes will be measured before and after three different montages of tDCS.
    

Intervention name(s): Transcranial direct current stimulation (tDCS)
Intervention type(s): Device
Intervention description(s): See detail in arm/group descriptions regarding the intervention.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: A three arm/group parallel interventional study model.
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: obsessive-compulsive disorder; treatment resistance; EEG; transcranial direct current stimulation