Noninvasive Brain Stimulation Combined With Written Exposure Therapy for PTSD in Military Personnel With TBI

In this study, the investigators are evaluating whether transcranial direct current stimulation (tDCS), a brain stimulation technique, can be combined with Written Exposure Therapy (WET), a standard talk therapy for posttraumatic stress disorder (PTSD) to improve treatment response and improve symptom of traumatic brain injury (TBI). After consenting to be in the study, participants will be asked to complete a baseline assessment of your psychological and physical health that will determine whether you are able to participate in the study. Following the baseline, you will be randomly assigned to receive tDCS or a sham/placebo. Everyone will also participate in 5 weekly WET psychotherapy sessions for 5 consecutive weeks. The first appointment will be 90 minutes and the subsequent appointments will be 60 minutes. tDCS or sham/placebo will occur during the writing portion of the session. All participants will also be asked to complete 1-, 3-, and 6-month posttreatment follow-up assessments.

Inclusion Criteria: 1. U.S military service member or veteran (18-70 years old) 2. PTSD diagnosis as assessed by Clinician-Administered Posttraumatic Stress Scale (CAPS-5-R) 3. History of mild to moderate Traumatic Brain Injury (TBI) 4. Able to speak, read, and write in English (due to assessment measures and writing intervention) Exclusion Criteria: 1. TBI that occurred within the past three months prior to the baseline assessment 2. History of significant intracranial pathology (e.g., severe TBI) 3. History of major neurological disorder (e.g., epilepsy, dementia) 4. Metallic objects other than dental appliances/fillings above the shoulders. 5. Electronic implants that could be susceptible to electrical current (e.g., cardiac pacemaker) 6. History of skin condition at site of stimulation (e.g., psoriasis) 7. Current suicidal ideation severe enough to warrant immediate attention 8. Current manic episode or psychotic symptoms requiring immediate stabilization or hospitalization 9. Current substance use requiring stabilization or hospitalization 10. Change in anti-convulsive or benzodiazepine medication regimen in past month. 11. History of adverse effects to previous noninvasive brain stimulation. 12. Concurrent engagement in another noninvasive brain stimulation or trauma focused psychotherapy. 13. Currently pregnant or breastfeeding.