TDCS-Augmented Prolonged Exposure Therapy

TDCS-Augmented Prolonged Exposure Therapy for PTSD: a Multiple Baseline Within-Subject Clinical Trial

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.

Inclusion Criteria:

• Age 18-65.
• Fluent in English.
• Diagnosis of chronic PTSD based on MINI for DSM-5 (> 3 mo. post-trauma)
• For Veterans recruited at the Ralph H. Johnson VA only: eligible to receive PE in the PCT clinic.

Exclusion Criteria:

• Currently receiving psychotherapy for another anxiety- or stress-related condition.
• Unstable dose of psychotropic medications within 6 weeks prior to baseline assessment
• Medical condition that would contraindicate participation in treatment or assessment activities (e.g., severe cardiovascular problems).
• Pregnancy
• Current severe major depressive disorder
• Current, or history of bipolar disorder
• Current, or history of psychotic symptoms
• Serious suicidal risk
• Active neurological conditions, e.g., seizures, stroke, loss of consciousness or concussion
• Contraindications for tDCS:
• Metal in the head.
• Implanted brain medical devices.