The 8-week study is one of the first designed to examine if dog interaction might benefit military veterans’ mental health. Researchers from Florida Atlantic University, the University of Maryland and Virginia Commonwealth University examined 33 veterans in Colorado (US), over half of whom identified as struggling with PTSD.
The veterans walked shelter dogs once a week along a pre-established walking path for four weeks. As a control group, the same participants also took walks with humans once a week along the same path.
The three biomarkers were: heart rate variability; cortisol (a "stress" hormone); and the enzyme alpha-amylase. The strongest indication that walking with a dog reduced stress came from heart rate variability findings. The heart rate variability biomarker was found to have the strongest correlation with human physical stress and psychosocial stress levels during and right after the walks.
Results showed that the veterans with PTSD had improved levels of both physiological and psychological stress indicators after their walks with both humans and dogs. But researchers also found these stress indicators were often better when the veterans walked with dogs. The improvement was even more notable in veterans with higher levels of reported PTSD symptoms.
PTSD affects 1 in 5 of the 21 million veterans living in the United States, and around 150,000 veterans living in the United Kingdom. Research shows that animal-assisted interventions (AAI) are linked to overall better health and stress management, and that adults with pets can experience better outcomes after suffering from a cardiovascular event such a stroke or a heart attack. Pets can also play an important role in helping to relieve loneliness and feelings of isolation.