Augmenting virtual reality exposure for PTSD with physical activity: study protocol of a randomised controlled trial

<b>Background:</b> Physical activity is increasingly incorporated in trauma-focused treatments as an augmentation strategy to improve treatment outcome. In a novel VR exposure treatment known as 3MDR (Multi-modal Motion-assisted Memory Desensitization and Reconsolidation), patients engage in low-intensity physical activity by walking on a treadmill throughout the therapy session, approaching trauma-related pictures that progressively enlarge until fully displayed in a VR environment. Physical activity is considered a key augmentation strategy in this treatment, with the proposed mechanism that walking toward a trauma-related picture facilitates the reduction of trauma-related avoidance, thereby improving treatment outcome. However, neither the specific effect of walking during this treatment nor the proposed working mechanism have been scientifically examined yet.<b>Objective:</b> In this paper we describe the rationale and study design of a randomised controlled trial (RCT) to examine the specific effect of walking toward trauma-related stimuli during VR exposure on treatment outcome. In addition, we will test whether walking toward trauma-related pictures facilitates a greater reduction in trauma-related avoidance.<b>Method:</b> Patients with PTSD (<i>N</i> = 158) are randomised to two treatment conditions: <b>walking</b> (VR exposure while walking) or <b>stationary</b> (VR exposure without walking), while keeping all other treatment aspects constant. Participants in both conditions receive two preparatory treatment sessions, 6 or 12 VR exposure sessions, and one closure session. The primary outcome is clinician-rated PTSD symptom severity. Secondary outcomes are both clinician-rated- and self-reported trauma-related avoidance symptom severity, as well as self-reported PTSD symptom severity. Assessments take place pre- and after 6 and 12 VR exposure sessions (posttreatment), and at 3-, 6-, 12- and 18- months follow-up.<b>Conclusion:</b> This RCT aims to examine whether incorporating walking during trauma-focused treatment in a VR exposure environment augments the treatment of patients with PTSD.