34 - Service Dog Training Program improves the serum cortisol and brain derived neurotropic factor (BDNF) in service members with Post-Concussive Symptoms and Post Traumatic Stress.

Abstract Text:

Background: Traumatic Brain Injury (TBI) and Post-traumatic stress disorder (PTSD) remain of high concern to the Department of Department of Defense as the incidence and prevalence of these disorders has increased since military operations began in Iraq and Afghanistan nearly two decades ago. Reports indicate that up to 20% of service members serving on active duty since 2001 have sustained a TBI from either a blast or impact related event. Similar numbers (10-20%) are reported for the incidence of PTSD among veterans. Multiple studies have also demonstrated that TBI and PTSD are often co-occurring with overlapping symptoms, such as difficulty concentrating, regulating emotions, disturbed sleep, and chronic pain, including headaches. It is estimated that nearly 1.7 million civilians sustain TBI every year, and many of them live with long term functional deficits.
Unfortunately, treatment options for individuals with TBI and PTSD is often limited, either by access to care for veterans, lack of follow-up, or the high rate of side-effects of many pharmacological agents. Therefore, more effective and safe therapeutic agents are needed in treating these conditions. A Service Dog Training Program (SDTP), which involves teaching patients with TBI and PTSD how to train service dogs, has been proposed as a safe and engaging alternative in augmenting the treatment of individuals with TBI and PTSD. A 2020 retrospective analysis of one SDTP found that service members who participated in the program twice per month had 18% fewer mental health encounter days and required 22% fewer monthly psychotropic prescription medications post-intervention, than those who participated in in the SDT less than twice per month. There is also anecdotal evidence of improved health, well-being, and relationships with loved ones. However, no research has been published to date regarding post-concussion syndrome (PCS) and PTSD-related biomarkers or the underlying molecular pathways at play during participation in a SDTP.


Objective: A multi-site clinical study to examine the effectiveness of a SDTP, this study aim is to investigate the effects of a SDT on serum levels of cortisol and brain derived neurotropic factor (BDNF), two molecular markers often implicated in post-concussion syndrome (PCS) and PTSD.

Methods: Blood samples were collected and analyzed for serum cortisol and BDNF levels. Only participants who provided at least two blood samples throughout the study were included in the analysis. The SDTP (described above) was conducted in two 1-hour sessions per week, for six weeks. Blood samples were collected at baseline (pre-intervention), midpoint (after receiving 3 weeks of intervention) and completion of the SDTP (after receiving 6 weeks of intervention), as well as at a follow-up visit (12 weeks after completing intervention). Serum cortisol and BDNF levels were evaluated using specific ELISA assays (Ray Biotech Inc). ELISA data were analyzed for statistical significance using GraphPad prism.

Results: A total of 202 biosamples were analyzed. Preliminary results show significantly reduced levels of serum cortisol at the midpoint (after 3 weeks of intervention), completion (after 6 weeks of intervention), and follow-up visit (12 weeks post-completion) compared to baseline cortisol concentrations. In addition, we observed an increased serum concentration of BDNF in participants at completion (after 6 weeks of intervention) compared to baseline levels.

Conclusions: Elevated levels of cortisol and reduced levels of BDNF have been associated with chronic stress and more severe PTSD symptoms, respectively. Our findings of significantly reduced cortisol levels and significantly increased BDNF levels following participation in a SDTP show improvement in underlying molecular markers associated with PCS and PTSD. These findings suggest an underlying physiological response to participation in a SDTP, consistent with proposed biological models of PTSD and TBI.

Disclaimers:
The opinions and assertions expressed herein are those of the authors and do not necessarily reflect the official policy or position of the Uniformed Services University or the Department of Defense or the U.S. Government.

The opinions and assertions expressed herein are those of the authors and do not necessarily reflect the official policy or position of the Henry M. Jackson Foundation for the Advancement of Military Medicine.

Keywords: Biomarker, Service dog Training, TBI, PTSD