Randomized controlled trial of two internet-based written therapies for world trade center workers and survivors with persistent PTSD symptoms.

Posttraumatic stress disorder (PTSD) remains prevalent among individuals exposed to the 9/11 World Trade Center (WTC) terrorist attacks. The present study compared an Internet-based, therapist-assisted psychotherapy for PTSD to an active control intervention in WTC survivors and recovery workers with WTC-related PTSD symptoms (n = 105; 75% syndromal PTSD). Participants were randomized to integrative testimonial therapy (ITT), focused on WTC-related trauma, or modified present-centered therapy (I-MPCT), each comprising 11 assigned written narratives. The primary outcome was baseline-to-post-treatment change in PTSD symptoms on the PTSD Checklist for DSM-5 (PCL-5). Secondary measures included PTSD symptom clusters, depressive/anxiety symptoms, functioning, and quality of life. A significant main effect of time was observed for the primary outcome (average "large" effect size improvement, d = 1.49). Significant and "moderate-to-large" main effects of time were also observed for all PTSD symptom clusters, depressive symptoms, quality of life, and mental health-related functioning (d range=0.62-1.33). Treatment and treatment-by-time interactions were not significant. In planned secondary analyses incorporating 3-month follow-up measures, ITT was associated with significantly greater reductions than I-MPCT in PTSD avoidance and negative alterations in cognitions and mood, anxiety, and mental health-related functioning. Both therapies significantly lowered PTSD symptoms, suggesting they may benefit hard-to-reach individuals with chronic WTC-related PTSD symptoms.