Effectiveness and Acceptability of Stellate Ganglion Block for Posttraumatic Stress Disorder Symptoms - Effectiveness

Study intervention will be administered at week 0 and at week 2. Injections will be performed under ultrasound visualization. The study medication will be either 7-10 mL 0.5% ropivacaine injected ventral to the right longus coli muscle (around and into the ventral fascia) and into the longus coli immediately dorsal to the presumed ventral fascia at the level of the C6 anterior tubercle (landmarks for the stellate ganglion) (active study medication) or 1-2 mL preservative free normal saline injected anterolateral to the anterior tubercle of C6 (sham procedure). The participant will not be informed which treatment he or she has received and the interaction of the participant and treating physician will be scripted as much as possible. Following the intervention, the treating physician should have no further contact with the participant except as required for participant safety. Participants will be evaluated for posttraumatic stress disorder (PTSD) symptomatology prior to week 0 and at 8 weeks using the Diagnostic and Statistical Manual (DSM-5) Clinician-Administered PTSD Scale (CAPS-5). They will complete the PTSD Checklist for DSM-5 (PCL-5), the PTSD Checklist - Civilian Version (PCL-C), and the Mini-international Neuropsychiatric Interview (M.I.N.I.-Plus) Suicidality Items at 0, 2, 4, 6, and 8 weeks; they also will complete the M.I.N.I.-Plus items at screening. The 12 item short form survey (SF-12), generalized anxiety disorder 7-item (GAD-7), patient health questionnaire (PHQ-9), K6, Alcohol Use Disorder Identification Test (AUDIT-C/AUDIT), and a short pain scale will be completed at weeks 0, 4, and 8. Data collected at baseline and 8 weeks will be the primary focus of data analysis. Data collected at other time points will be analyzed as appropriate.