Psychophysiological response to virtual reality and subthreshold posttraumatic stress disorder symptoms in recently deployed military

Objective: Subthreshold posttraumatic stress disorder (PTSD) has garnered recent attention because of the significant distress and functional impairment associated with the symptoms as well as the increased risk of progression to full PTSD. However, the clinical presentation of subthreshold PTSD can vary widely and therefore is not clearly defined, nor is there an evidence-based treatment approach. Thus, we aim to further the understanding of subthreshold PTSD symptoms by reporting the use of a virtual combat environment in eliciting distinctive psychophysiological responses associated with PTSD symptoms in a sample of subthreshold recently deployed US service members. Methods: Heart rate, skin conductance, electromyography (startle), respiratory rate, and blood pressure were monitored during three unique combat-related virtual reality scenarios as a novel procedure to assess subthreshold symptoms in a sample of 78 service members. The Clinician-Administered PTSD Scale was administered, and linear regression analyses were used to investigate the relationship between symptom clusters and physiological variables. Results: Among the range of psychophysiological measures that were studied, regression analysis revealed heart rate as most strongly associated with Clinician- Administered PTSD ScaleYbased measures hyperarousal (R² = 0.11, p = .035,) reexperiencing (R² = 0.24, p = .001), and global PTSD symptoms (R² = 0.17, p = .003). Conclusions: Our findings support the use of a virtual reality environment in eliciting physiological responses associated with subthreshold PTSD symptoms.