IMG via Fox Business 

Are dogs really human’s best friend? Scientific research has tested the common belief that dogs and other pets can improve our quality of life. Let’s think twice: can our furry friends reduce stress?  

In one controlled trial of 82 university students (1), half watched videos of dogs, while the other half interacted with a dog directly. While both sets of students experienced decreased stress, the decrease was greater for students who interacted directly with the dogs. While the sample size is relatively small, it is sufficient to detect a large effect.  But the experimental groups were not randomly assigned, so other factors may account for the findings.  

A similar randomized control trial of university students and medical residents found that interacting with a dog reduced anxiety and negative mood more than viewing the dog or no exposure (2).   

A study of 53 adolescents diagnosed with post-traumatic stress disorder assigned 30 participants to a dog-training program and 23 to other training programs such as cooking and hairstyling according to their personal interests, (3). Researchers found that the individuals who worked with dogs experienced a greater alleviation in PTSD symptoms and lower depression severity compared to those not working with dogs. 

A study of military veterans and ex-first responders diagnosed with PTSD found that people with service dogs had significantly fewer PTSD-related symptoms, better sleep quality, and better wellbeing. There may be other factors (scientists call these confounders) associated with having a service or companion dog such as greater social support or agency, so a randomized trial is needed to confirm this finding.   

Many of us feel it’s obvious that dogs relieve stress.  But that’s exactly why good experimental science is needed to be certain.  Otherwise, we’ll just prove our bias.  To date, the evidence available does not adequately account for bias and potential confounders. Randomized trials with blinding of evaluators would help.  But it’s not clear what would constitute an adequate control for a live dog companion.  

 

References:

1. Thelwell E. L. R. (2019). Paws for Thought: A Controlled Study Investigating the Benefits of Interacting with a House-Trained Dog on University Students Mood and Anxiety. Animals : an open access journal from MDPI, 9(10), 846. https://doi.org/10.3390/ani9100846  
2. Crossman, M. K., Kazdin, A. E., Matijczak, A., Kitt, E. R., & Santos, L. R. (2020). The Influence of Interactions with Dogs on Affect, Anxiety, and Arousal in Children. Journal of clinical child and adolescent psychology : the official journal for the Society of Clinical Child and Adolescent Psychology, American Psychological Association, Division 53, 49(4), 535–548. https://doi.org/10.1080/15374416.2018.1520119 
3. Maoz, I., Zubedat, S., Dolev, T., Aga-Mizrachi, S., Bloch, B., Michaeli, Y., Eshed, Y., Grinstein, D., & Avital, A. (2021). Dog training alleviates PTSD symptomatology by emotional and attentional regulation. European journal of psychotraumatology, 12(1), 1995264. https://doi.org/10.1080/20008198.2021.1995264 
4. van Houtert, E. A. E., Rodenburg, T. B., Vermetten, E., & Endenburg, N. (2022). The Impact of Service Dogs on Military Veterans and (Ex) First Aid Responders With Post-traumatic Stress Disorder. Frontiers in psychiatry, 13, 834291. https://doi.org/10.3389/fpsyt.2022.834291