In a pilot study, scientists successfully trained dogs to recognize stress cues from the breathing of humans who were reflecting on past traumatic experiences. Some service dogs can already alert to physical cues of post-traumatic stress disorder (PTSD) symptoms, but dogs that can sniff out early warnings can help patients know that an episode has begun. You may act to help your spouse earlier, before you are consciously aware of it, and your intervention may be more effective. effective.
A dog’s sensitive nose can detect early warning signs of many potentially dangerous medical situations, such as an impending seizure or sudden hypoglycemia. Now, scientists have produced evidence that assistance dogs may even be able to sniff out an impending PTSD flashback by teaching two dogs to pay attention to the breathing of a person who has recalled the trauma. discovered.
“Service dogs with PTSD are already trained to help people in distress,” said lead author Laura Kiiroja of Dalhousie University. Allergy frontier. “But dogs are now trained to respond to behavioral and physical cues. Our study showed that at least some dogs can also detect these symptoms in their breath. .”
Stressed people smell
PTSD is caused by exposure to a catastrophic event. Symptoms include re-experiencing the catastrophic event, hyperarousal, avoiding reminders, and cognitive and mood problems. Among other forms of assistance, dogs can help patients by alerting them when their companion is suffering from symptoms and interrupting the episode. If the dog can respond to respiratory stress markers, it may be possible to interrupt the episode earlier and the intervention may be more effective.
All humans have a “scent profile” of volatile organic compounds (VOCs) (molecules released by the body in secretions such as sweat) that are influenced by genetics, age, activity, and other variables. Masu. There is some evidence that dogs may be able to detect stress-related VOCs in humans. However, no studies have investigated whether dogs can detect VOCs associated with her PTSD symptoms. “This is an interdisciplinary collaboration between Dr Shelley Stewart’s clinical psychology laboratory and Dr Simon Gadbois’ canine olfaction laboratory at Dalhousie University,” Professor Kiiroja said. “Neither lab could have done this research alone. We brought together two different expertises.”
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catch the scent
Scientists recruited 26 humans to act as scent donors. These participants were also participating in a study of how people who have experienced trauma react when reminded of that trauma. 54% met her diagnostic requirements for PTSD. To donate scent, they participated in a session in which they were reminded of their traumatic experiences while wearing different face masks. One facemask provided a mild breath sample that served as a control, and the other facemask was worn by participants when recalling the trauma and provided a target breath sample. Participants also completed questionnaires regarding their stress levels and emotions.
During that time, scientists recruited 25 pet dogs to be trained in scent detection. Only two of him, Ivy and Curry, were skilled and motivated enough to complete this research.
“Both Ivy and Curry found the work inherently motivating,” Kiiroja said. “Their endless appetites for tasty treats were also an asset. In fact, it was much more difficult to convince them to take a break than to start working. Callie in particular was anxious to make sure there was no boring life. were handing out.”
Ivy and Carrie were trained to recognize target odors from pieces of face masks, and achieved 90% accuracy in distinguishing between stressed and unstressed samples. He was then presented with a series of samples, one at a time, to see if he could accurately detect stress VOCs. In this her second experiment, Ivy achieved her 74% accuracy and Callie achieved her 81% accuracy.
man’s best friend
Comparing Callie and Ivy’s successful identification with human participants’ self-reported emotions revealed that Ivy’s performance correlated with anxiety, whereas Callie’s performance correlated with shame. Ta.
“Both dogs performed with very high accuracy, but they seemed to have slightly different ideas about what constituted a ‘stressed’ breath sample,” Kiiroja said. “We suspect that Ivy is attuned to hormones in the sympathetic-adrenal medullary axis (e.g., adrenaline) and Callie is attuned to hormones in the hypothalamic-pituitary-adrenal axis (e.g., cortisol). We speculated: This is important knowledge for service dog training, as sensitivity to sympathetic-adrenal-bulbar axis hormones is needed to alert to early-onset PTSD symptoms.”
The research team next plans to conduct experiments to confirm the involvement of the sympathetic-adrenal-medulla axis.
“Our study with a sample set of 40 is a proof-of-concept study and needs to be validated by studies with larger sample sizes,” Kiiroja cautioned. “In addition to enrolling more participants, the validation study will collect samples from more stressful events to reliably detect stress VOCs in the breath of a single person in a variety of situations.” You need to check the dog’s abilities.
