Enhancing cognitive processing therapy via stellate ganglion blocks: A pilot randomized trial

Although trauma-focused psychotherapies, such as cognitive processing therapy (CPT), are effective treatments for posttraumatic stress disorder (PTSD), a substantial portion of individuals exhibit a diminished response. Stellate ganglion block (SGB), an anesthetic procedure targeting the sympathetic nervous system, has shown promise for PTSD but has only recently begun to be evaluated as an augmentation to evidence-based psychotherapy. This randomized, placebo-controlled, double-blind pilot trial assessed the efficacy of 1-week accelerated CPT augmented with SGB versus a placebo injection. Of 54 consented individuals, 39 participants (M_age = 38.1 years, SD = 11.0; 69.2% female; 79.5% White) who met the DSM-5 criteria for PTSD were randomized to receive SGB (n = 18) or a saline injection (n = 21), followed by 10 virtual CPT sessions over 5 days. The primary outcome was clinician-assessed PTSD severity (Clinician-Administered PTSD Scale for DSM-5; CAPS-5); secondary outcomes included self-reported PTSD (PTSD Checklist for DSM-5; PCL-5) and depressive symptoms (Patient Health Questionnaire-9; PHQ-9). Of 39 randomized participants, 37 (94.9%) completed treatment. Both groups experienced large improvements in PTSD symptoms, CAPS-5 (baseline-3-months): d = 1.77, PCL-5: d = 1.67, and depressive symptoms, PHQ-9: d = 0.86. Treatment Condition x Time interactions were not significant for the CAPS-5, PCL-5, or PHQ-9, ps = .144-.958. Post hoc comparisons indicated significantly lower PCL-5 scores in the SGB group on Day 1 of CPT, B = -11.99, p = .015. Augmenting accelerated CPT with SGB was highly feasible but did not produce significantly larger symptom reductions compared to placebo.