Quetiapine as an adjunct to enhance engagement in prolonged exposure therapy for PTSD in veterans: A randomized, pilot trial

Despite established efficacy, there is low engagement in prolonged exposure (PE) therapy for PTSD among combat veterans. In preparation for a full-scale randomized trial, we sought to evaluate the feasibility, safety, and preliminary efficacy of quetiapine to enhance patient engagement in PE therapy. Open-label, randomized pilot trial of quetiapine monotherapy vs. Treatment as Usual (TAU) medications in 20 military veterans with combat related PTSD who were seeking care from the San Antonio Polytrauma Rehabilitation Center at the South Texas Veterans Healthcare System (STVHCS). Participants were randomized to receive either Quetiapine (n = 10) monotherapy or pharmacological TAU (n = 10) in patients who were receiving PE as a standard of care therapy. We collected information on (1) the number of potentially eligible veterans approached, the number screened, and the number randomized, (2) adverse events reported, (3) number of participants continuing PE treatment at least until session #4 (i.e., after first exposure session) and the total number of sessions of PE completed by the participants, and (4) change in PTSD severity and sleep quality measured by the PTSD Checklist for DSM-5 (PCL-5) and Pittsburgh Sleep Quality Index (PSQI). Data were analyzed for 18 intent-to-treat participants with mean (SD) age, 53.5 (13.4) years; and baseline PCL-5 score, 57.6 (7.6). More veterans in the quetiapine group (n = 9; 100%) received at least the first exposure session of PE therapy compared to TAU ((n = 3; (37.5%), p = .006] and completed PE therapy (n = 8; (88.9%) vs (n = 3; (37.5%), p = .03). Both PCL-5 (p = .03) and PSQI (p = .02) scores decreased significantly more for participants in the quetiapine than the TAU group. Preliminary findings support the feasibility, safety, and possible efficacy of quetiapine as an adjunct to enhancing engagement in PE therapy. A full-scale randomized trial is required to determine the true efficacy of quetiapine to enhance engagement in PE treatment.