tDCS Plus Virtual Reality for PTSD
Condition: Post-Traumatic Stress Disorder
MeSH terms: Stress Disorders, Traumatic; Stress Disorders, Post-Traumatic
Study type: Interventional

Summary: 
      This study will test the effectiveness of combining non-invasive brain stimulation, called
      transcranial direct current stimulation (tDCS), with virtual reality exposure as a treatment
      for Veterans with chronic posttraumatic stress disorder (PTSD). Investigators will test
      whether this intervention improves PTSD symptoms and improves quality of life. Results from
      this study may be used to develop a new non-medication approach to treating chronic PTSD.
    

Detailed description: 
      PTSD is highly prevalent in Veterans and is associated with significant psychiatric and
      medical comorbidity, as well as poor quality of life. Despite its prevalence and impact, the
      success of currently available treatments is mixed, highlighting the need for novel
      approaches that aim to reduce symptoms and improve outcomes. Prior research has demonstrated
      that reduced activity in a part of the brain, the ventromedial prefrontal cortex (VMPFC), is
      associated with an inability to regulate fear responses, preventing the generation of safety
      memories and allowing PTSD symptoms to persist. Targeting the VMPFC with non-invasive
      electrical brain stimulation may therefore alleviate these symptoms.

      Transcranial direct current stimulation (tDCS) is a type of non-invasive brain stimulation
      that may enhance the likelihood of neuronal activity in the VMPFC. In doing so, tDCS prepares
      the brain to respond to external stimuli and to facilitate learning and memory. Because
      therapeutic success from exposure to trauma-related content - as used in exposure-based
      therapy for PTSD - is thought to be based on an adaptive learning process, applying tDCS in
      combination with exposure to trauma cues may effectively boost exposure-based learning. To do
      this, investigators at the Providence VA Medical Center will use a standardized virtual
      reality (VR) setting to deliver trauma-related content. The virtual reality setting involves
      three, 8-minute driving scenarios, which consist of VR stimuli (sights, sounds, smells, etc.)
      often encountered in combat training and in theater.

      Eligible participants will be randomized to receive six sessions of either active tDCS plus
      virtual reality (tDCS+VR) or sham tDCS+VR. Clinical and self-report assessments will be
      completed at baseline, midpoint, and endpoint, as well as 1 and 3 months following the final
      tDCS+VR session. Participants will also undergo a MRI before and after completion of all six
      tDCS+VR sessions to assess change over time. Additionally, MRI data will be used for
      electrical field modeling to predict treatment response based on individually obtained
      electrical field values in PTSD relevant neural circuitry. Participants may also choose to
      participate in an optional pre-tDCS+VR session EEG and an optional 1-month follow-up MRI.
    

Intervention name(s): Active stimulation; Sham stimulation; Virtual Reality (VR)
Intervention type(s): Device; Device; Other
Intervention description(s): For active tDCS, the investigators will use a 1x1 configuration with the anode placed over EEG coordinates AF7/Fp1/AF3 (using the 10-20 EEG convention) and the cathode between EEG coordinate OZ and the contralateral mastoid (covering approximately PO8/P8). The investigators will use 3x3 cm sponge covered electrodes and a 2mA current for 25 minutes per session.; For sham tDCS, the investigators will use the same electrode and sponge configuration as active tDCS, but using the device study mode (10 µA over 15 ms current pulse applied every 550 ms, 3ms peak current).; Participants will undergo VR exposure to trauma-related context.
Other intervention name(s): Active tDCS; Sham tDCS
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants are assigned to receive either active or sham stimulation during the tDCS+VR sessions in parallel for the duration of the study
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Transcranial Direct Current Stimulation; Stress Disorders, Post-Traumatic; Virtual Reality; Prefrontal Cortex; Veterans; Quality of Life