A pilot study of interpersonal process group therapy for PTSD in Canadian veterans

Abstract: Introduction: The present pilot study was designed to explore interpersonal process (IP) group therapy for post-traumatic stress disorder (PTSD); a novel and relatively untested treatment approach for PTSD. IP groups seek to normalize patients’ symptoms and enhance functioning by creating a safe environment wherein participants can engage with others who share similar experiences and symptoms. Methods: Present IP groups met weekly for 12 weeks. Participants included 20 Canadian male Veterans and RCMP officers (10 per treatment group) with a primary diagnosis of PTSD. All participants had previously received first-line treatments for PTSD but continued to experience serious limitations in functioning. Key measures of interest (i.e., PTSD, negative affect, moral injury) were administered immediately pre- and post-intervention. Qualitative data was collected from a subset of participants (n = 6). Results: Baseline scores revealed significantly elevated symptom levels compared to normative and clinical samples. Retention rate over the course of therapy was 100%, a rare and important finding in clinical research generally, and in the PTSD population more specifically. Qualitative feedback was consistently positive; feedback also suggested future potential improvements for the therapeutic intervention. There was a significant reduction in anxiety (specifically, physiological hyperarousal) pre- to post-intervention, with a partial eta squared (n2 p) value of 0.26, indicating a large effect size. Discussion: Examination of individual scores showed that fully one-third of participants demonstrated a reliable improvement in both physiological anxiety and anxiety sensitivity (AS), both of which have been implicated in the exacerbation and maintenance of other PTSD symptoms. Results support a randomized controlled trial of group IP for PTSD.