A randomized controlled trial of yoga vs nonaerobic exercise for veterans with PTSD: Understanding efficacy, mechanisms of change, and mode of delivery

BACKGROUND AND OBJECTIVES: Posttraumatic stress disorder (PTSD) is a chronic, disabling, and prevalent mental health disorder among Veterans. Despite the availability of empirically supported psychotherapies, many Veterans remain symptomatic after treatment and/or prefer to seek complementary and integrative health approaches, including yoga, to manage PTSD. The randomized controlled trial (RCT) described herein will evaluate the efficacy of a manualized yoga program as compared to nonaerobic exercise in reducing PTSD severity among Veterans. A secondary aim of this study is to better understand the mechanisms of change. METHODS: Veterans (N = 192) with PTSD will be randomized to hatha yoga or nonaerobic physical activity control; both groups consist of 12 weekly, 60-min group or online training sessions with 15–20 min of daily at-home practice. Outcome measures will be administered at baseline, mid-treatment, posttreatment, and 12-week follow-up. PROJECTED OUTCOMES: This study will evaluate changes in PTSD severity (primary outcome) as well as depression, anxiety, anger, sleep problems, and psychosocial disability (secondary outcomes). We will also use multiple mediation to examine two potential models of the mechanisms of clinical effect: the Attention Model (i.e., yoga increases attentional control, which reduces PTSD symptoms), the Coping Model (i.e., yoga increases distress tolerance, which improves coping, which reduces PTSD symptoms), and the combination of these models. This aspect of the study is innovative and important given the absence of an existing, comprehensive model for understanding yoga's impact on PTSD. Ultimately, we hope to develop guidelines for application of yoga to PTSD recovery.