Dogs may recognize post-traumatic stress through their sense of smell

Dogs may recognize post-traumatic stress through their sense of smell

Dogs are known for their highly developed sense of smell, which is estimated to be 10,000 times more powerful than that of humans. This flair proves very useful in the detection of several diseases, including diabetes, malaria and certain cancers. It could even prevent and limit the effects of post-traumatic stress, according to a Canadian study.

The authors of this study, published in the journal Frontiers in Allergy, reached this conclusion after conducting an experiment with 26 people suffering from post-traumatic stress disorder. As a reminder, post-traumatic stress disorder refers to psychiatric disorders that occur after a traumatic event. It manifests itself through repeated relivings of the trauma, with flashbacks and nightmares, and physical complications which profoundly alter the personal, social and professional lives of those who suffer from it.

Study participants donned face masks before being put into a state of stress, so researchers could take a sample of their breath. These samples were then presented to Ivy and Callie, two dogs who had previously been trained to sense stress. Indeed, a research team from Queen’s University Belfast previously discovered that canines can detect chemical changes at work in stressed people in their breath and sweat.

Ivy and Callie were able to distinguish between breath samples from a person suffering from post-traumatic stress disorder, with an accuracy rate of 90%. However, the scientists noticed that the two dogs did not seem to perceive the same odorous volatile organic compounds in the volunteers’ breath. “We hypothesized that Ivy responded more to hormones of the sympatho-adrenal system such as adrenaline, and Callie to those of the hypothalamic-pituitary-adrenal axis such as cortisol.“said Laura Kiiroja, first author of the study, in a press release.

The conclusions of this study should, however, be taken with caution given the small number of participants. Nevertheless, they open up new perspectives regarding the role of assistance dogs in the care of individuals suffering from post-traumatic stress. Their ability to detect the warning signs of a crisis could transform the way this psychiatric disorder is treated, and allow people who suffer from it to have a better life.