Massed vs Intensive Outpatient Prolonged Exposure for Combat-Related Posttraumatic Stress Disorder: A Randomized Clinical Trial

Abstract

Importance: Improved, efficient, and acceptable treatments are needed for combat-related posttraumatic stress disorder (PTSD).

Objective: To determine the efficacy of 2 compressed prolonged exposure (PE) therapy outpatient treatments for combat-related PTSD.

Design, setting, and participants: This randomized clinical trial was conducted among military personnel and veterans at 4 sites in Texas from 2017 to 2019. Assessors were blinded to conditions. Data were analyzed from November 2020 to October 2022.

Interventions: The interventions were massed-PE, which included 15 therapy sessions of 90 minutes each over 3 weeks, vs intensive outpatient program PE (IOP-PE), which included 15 full-day therapy sessions over 3 weeks with 8 treatment augmentations. The IOP-PE intervention was hypothesized to be superior to massed-PE.

Main outcomes and measures: Coprimary outcomes included the Clinician-Administered PTSD Scale for Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (DSM-5) (CAPS-5) and the PTSD Checklist for DSM-5 (PCL-5) administered at baseline and posttreatment follow-ups. Measures ranged from 0 to 80, with higher scores indicating greater severity. Diagnostic remission and reliable change were secondary outcomes.

Results: Among 319 military personnel and veterans screened, 234 were randomized (mean [SD] age, 39.20 [7.72] years; 182 [78%] male participants), with 117 participants randomized to IOP-PE and 117 participants randomized to massed-PE. A total of 61 participants (26%) were African American, 58 participants (25%) were Hispanic, and 102 participants (44%) were White; 151 participants (65%) were married. Linear mixed-effects models found that CAPS-5 scores decreased in both treatment groups at the 1-month follow-up (IOP-PE: mean difference, -13.85 [95% CI, -16.47 to -11.23]; P < .001; massed-PE: mean difference, -14.13 [95% CI, -16.63 to -11.62]; P < .001). CAPS-5 change scores differed from 1- to 6-month follow-ups (mean difference, 4.44 [95% CI, 0.89 to 8.01]; P = .02). PTSD symptoms increased in massed-PE participants during follow-up (mean difference, 3.21 [95% CI, 0.65 to 5.77]; P = .01), whereas IOP-PE participants maintained treatment gains (mean difference, 1.23 [95% CI, -3.72 to 1.27]; P = .33). PCL-5 scores decreased in both groups from baseline to 1-month follow-up (IOP-PE: mean difference, -21.81 [95% CI, -25.57 to -18.04]; P < .001; massed-PE: mean difference, -19.96 [95% CI, -23.56 to -16.35]; P < .001) and were maintained at 6 months (IOP-PE: mean change, -0.21 [95% CI, -3.47 to 3.06]; P = .90; massed-PE: mean change, 3.02 [95% CI, -0.36 to 6.40]; P = .08). Both groups had notable PTSD diagnostic remission at posttreatment (IOP-PE: 48% [95% CI, 36% to 61%] of participants; massed-PE: 62% [95% CI, 51% to 73%] of participants), which was maintained at 6 months (IOP-PE: 53% [95% CI, 40% to 66%] of participants; massed-PE: 52% [95% CI, 38% to 66%] of participants). Most participants demonstrated reliable change on the CAPS-5 (61% [95% CI, 52% to 69%] of participants) and the PCL-5 (74% [95% CI, 66% to 81%] of participants) at the 1-month follow-up.

Conclusions and relevance: These findings suggest that PE can be adapted into compressed treatment formats that effectively reduce PTSD symptoms.

Trial registration: ClinicalTrials.gov Identifier: NCT03529435.

Conflict of interest statement

Conflict of Interest Disclosures: Dr Foa reported receiving personal fees from Edna B. Foa and Oxford University Press outside the submitted work. Dr Brown reported receiving grants from Department of Defense and National Institute of Mental Health outside the submitted work. Dr Jacoby reported receiving grants from Texas Department of Family and Protective Services and personal fees from Evidence Based Practice outside the submitted work. No other disclosures were reported.

Figures

Figure 1.. Participant Recruitment Flowchart

IOP-PE indicates intensive outpatient program prolonged exposure; M-PE, massed prolonged exposure; PTSD, posttraumatic stress disorder.

Figure 2.. Changes in Assessment Scores by Treatment Group

B-IPF indicates Brief Inventory of Psychosocial Functioning; CAPS-5, Clinician-Administered PTSD Scale for Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (DSM-5); IOP-PE, intensive outpatient program prolonged exposure; M-PE, massed prolonged exposure; PCL-5, PTSD Checklist for DSM-5; SDS, Sheehan Disability Scale.

Figure 3.. Posttraumatic Stress Disorder (PTSD) Diagnostic Remission Rate and Reliable Change Index (RCI) by Treatment Group

CAPS-5 indicates Clinician-Administered PTSD Scale for Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (DSM-5); IOP-PE, intensive outpatient program prolonged exposure; M-PE, massed prolonged exposure; and PCL-5, PTSD Checklist for DSM-5.