Feasibility of intensive prolonged exposure for PTSD: a pragmatic pilot study in Swedish public outpatient psychiatry

BACKGROUND: Prolonged exposure (PE) is an established treatment for PTSD, but outcomes are often limited by dropout and delivery constraints. This study evaluated the feasibility, acceptability, and preliminary effectiveness of intensive-format PE (I-PE) delivered as a pragmatic intervention in a Swedish psychiatric outpatient setting. METHODS: Thirty-three adults meeting the diagnostic criteria for PTSD were enrolled in a single-center, uncontrolled pragmatic feasibility trial embedded in routine outpatient care in Sweden. I-PE comprised five consecutive days of therapist-guided treatment, followed by three individual booster sessions at weeks 2, 4, and 8. The primary objectives were to assess feasibility through reach, retention, treatment adherence, satisfaction, and safety. Clinical outcomes included clinician-rated PTSD severity with the Clinician-Administered PTSD Scale for DSM-5 at baseline and 6-month follow-up; self-reported PTSD with the PTSD Checklist for DSM-5 at baseline, posttreatment, and 6-month follow-up; complex PTSD symptoms with the International Trauma Questionnaire at baseline and posttreatment; and depression with the Patient Health Questionnaire-9 and quality of life with the EuroQol 5-Dimension at baseline, posttreatment, and 6-month follow-up. Analyses were conducted using mixed-effects linear models under an intention-to-treat framework. RESULTS: I-PE proved both feasible and acceptable within routine care; 97% (32/33) completed the full protocol, and no serious adverse events were reported. Treatment satisfaction was high, with 90% of participants indicating that they would recommend I-PE to a friend in need of similar help. Substantial reductions in PTSD symptoms were observed on both clinician- and self-rated measures from baseline to the 6-month follow-up. The within-group effect sizes were large for clinician-rated symptoms (Cohen’s d = 2.05 at 6-month follow-up) and self-reported symptoms (Cohen’s d = 1.05 posttreatment; d = 1.24 at 6-month follow up). CONCLUSIONS: Pragmatically delivered, I-PE shows promise as a time-efficient alternative to weekly care, with low dropout rates, and warrants fully powered controlled trials to establish efficacy, durability, and cost-effectiveness. TRIAL REGISTRATION: ClinicalTrials.gov (registration ID: NCT05207462) on December 22, 2021.