The purpose of this study is to determine the effects of a brain stimulation technique known as transcranial direct current stimulation, or tDCS, on the benefits of Prolonged Exposure therapy, or PE, which is an effective treatment for posttraumatic stress disorder, or PTSD. tDCS has been demonstrated to be safe and effective for influencing brain activity by passing a weak electrical current through the scalp. In this study, tDCS is provided in addition to PE treatment, through the National Crime Victim's Research and Treatment Center at MUSC, or the PTSD Clinical Team Clinic within the Ralph H. Johnson VA Medical Center.
This project implements a multiple baseline within-subject clinical trial design aiming to test whether tDCS targeting excitation of the medial prefrontal cortex (mPFC) can enhance a standard course of PE in a sample of adult civilians and Veterans (ages 18-65) who meet full DSM-5 criteria for chronic PTSD (i.e., \> 3 months post-trauma; N = 20). All participants will receive a total of ten 60-min. sessions of manualized PE, preceded by 20 min. of either active or sham HD-tDCS. The stepped-wedge multiple baseline design features tDCS as a 2-level within-subject factor (Sham tDCS+PE vs. Active tDCS+PE), and between-subject comparisons based on stratified random assignment to cross-over from sham to active tDCS just prior to sessions 4 through 8. Strata will be defined by dichotomous classifications of possible confounds, including baseline severity (moderate vs. severe), psychotropic medication status (no vs. yes), and sex (female vs. male). The sample will consist of treatment-seeking civilian and Veteran participants referred by either of two of our consortium sites, including the National Crime Victim's Research and Treatment Center (NCVC) at MUSC, or the PTSD Clinical Team (PCT) at the Ralph H. Johnson VAMC, as well as community participants who respond to study advertisements.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Participants will receive 20 min. of either sham or active tDCS prior to PE sessions using a 1 x 1 tDCS device with a ring electrode configuration that allows relatively excitatory and focal stimulation of the dorsomedial prefrontal cortex (dmPFC). Electrodes consist of sponges in a silicone rubber holder with a metal mesh conductor saturated with normal saline. A center anode (2.5 cm diameter) and a ring-shaped cathode (diameter inner/outer: 9.2/11.50 cm) will be centered over the dmPFC, with the anode placed the midline at 15% of the Fz to FPz distance. Active stimulation will commence with a 15 sec. ramping up period to target current (1.5 mA), followed by constant current for 20 min., and a 15 sec. ramping down period. For all sham sessions, stimulation will be immediately ramped down over a 15 sec. period following the initial ramping up period, and subsequently ramped up over 15 sec. prior to the final ramping down period.
All participants will receive 10 weekly sessions of standard Prolonged Exposure Therapy, or PE, which is a gold standard trauma-focused cognitive behavioral treatment for PTSD. The first sessions (1-2) predominately consist of psychoeducation about PTSD and the rationale for treatment, whereas subsequent sessions (3-10) consist of imaginal and in vivo exposure, involving repeated, prolonged, systematic, and deliberate practice approaching trauma reminders, as well as cognitive and emotional processing reactions to an index trauma memory.
National Crime Victim's Research & Treatment Center, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina
Charleston, South Carolina, United States
Change in Clinician-Rated PTSD Symptom Severity
Clinician-administered PTSD Symptom Scale Interview for DSM-5 (PSSI-5). Total scores range from 0 to 80, with higher scores indicating greater severity of PTSD symptoms.
Time frame: Pre-treatment (baseline), post-treatment (12 weeks post-baseline), and 1-month follow-up (16 weeks post-baseline)
Change in Self-Reported PTSD Symptom Severity
Self-report scores on the PTSD Symptom Checklist for DSM-5 (PCL-5) Total scores range from 0 to 80, with higher scores indicating greater severity of PTSD symptoms.
Time frame: Pre-treatment (baseline), post-treatment (12 weeks post-baseline), and 1-month follow-up (16 weeks post-baseline)
Change in Self-Reported Post-traumatic Cognitions
Self-report scores on the Post-traumatic Cognitions Inventory (PTCI-9) Total scores range from 9 to 63, with high scores indicating greater endorsement of common and problematic trauma-related beliefs.
Time frame: Pre-treatment (baseline), post-treatment (12 weeks post-baseline), and 1-month follow-up (16 weeks post-baseline)
Change in Depression Symptoms
Self-report scores on the Beck Depression Inventory, 2nd Edition (BDI-II) Total scores range from 0 to 63, with higher scores indicating greater severity of depression symptoms.
Time frame: Pre-treatment (baseline), post-treatment (12 weeks post-baseline), and 1-month follow-up (16 weeks post-baseline)
Change in Anxiety Symptoms
Self-report scores on the Beck Anxiety Inventory (BAI) Total scores range from 0 to 63, with higher scores indicating greater severity of anxiety symptoms.
Time frame: Pre-treatment (baseline), post-treatment (12 weeks post-baseline), and 1-month follow-up (16 weeks post-baseline)
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Within- and Between-Session Change in Trauma-Related Emotional Distress
Self-reported in-session Subjective Units of Distress Scale (SUDS) Peak distress among repeated ratings obtained during therapy sessions from 0 = "no distress" to 100 = "extreme distress". Ratings will be obtained up to 13 times at each weekly Prolonged Exposure therapy session, for 10 weeks.
Time frame: During weekly therapy sessions 1-10, for 10 weeks from baseline.
Within- and Between-Session Change in Heart Rate
Continuously recorded in-session heart rate Heart rate will be continuously recorded during each weekly Prolonged Exposure therapy session, for 10 weeks.
Time frame: During weekly therapy sessions 1-10, for 10 weeks from baseline.
Within- and Between-Session Change in Physiological Activation
Continuously recorded in-session skin conductance levels Skin conductance levels will be continuously monitored during each weekly Prolonged Exposure therapy session, for 10 weeks.
Time frame: During weekly therapy sessions 1-10, for 10 weeks from baseline.
Between-Session Change in Trauma Memory Engagement and Emotional Processing
Therapist-report scores on the Prolonged Exposure Therapist Questionnaire Total scores range from 0 to 35, with higher scores indicating greater retrieval, processing, and meaning making during imaginal revisiting of the index trauma memory.
Time frame: During weekly therapy sessions 1-10, for 10 weeks from baseline.