Multi-site, Longitudinal Trial Evaluating the Efficacy, Mechanisms, and Moderators of Service Dogs for Military Veterans With PTSD

Posttraumatic stress disorder (PTSD) among military Veterans is a critical public health concern. Veteran suicide rates exceed those of the general population, with the disorder creating a mental health challenge that is costly and debilitating. The majority of Veterans with PTSD also have comorbid mental health diagnoses, such as generalized anxiety disorder, substance abuse disorder, and major depression. The treatment of Veteran PTSD and comorbid disorders represents an important therapeutic and rehabilitation problem. The disorder is complex and difficult to treat, with high treatment dropout and nonresponse rates spurring some Veterans to seek complementary integrative health strategies. One promising complementary strategy is the provision of a trained service dog. Initial evidence across multiple research groups highlights service dogs as a promising complement to evidence-based practices that can offer short-term improvements. However, the long-term effectiveness, mechanisms of action, and moderators of efficacy remain largely unknown. Thus, the overarching objective of this proposal is to understand how, why, and for whom PTSD service dogs are most effective.

To address this objective, the present project will assess the longitudinal efficacy and dose-response curve of service dogs for Veteran PTSD symptomology and psychosocial functioning. The research design will consist of a two-arm, randomized clinical trial (RCT) with longitudinal assessments over a period of 15 months. Results are expected to elucidate the clinical impact of service dogs for military Veterans with PTSD, as well as the biobehavioral mechanisms of action and characteristics that moderate efficacy. These outcomes will support the long-term goal of accelerating complementary and integrative health interventions, through optimized and evidence-based service dog interventions. As such, this project will further advance the scientific understanding of human-animal interactions for psychosocial health.