Sniffing: Dal's pilot study finds dogs can smell trauma – Dal News

A dog's sensitive nose can pick up early warning signs of many potentially dangerous medical conditions, such as an impending seizure or sudden hypoglycemia in diabetics. Now, scientists have found evidence that service dogs may even be able to sniff out incoming post-traumatic stress disorder (PTSD) flashbacks.

“PTSD service dogs are already trained to help people during episodes of distress,” said Laura Kiiroja from the Department of Psychological and Neuroscience at Dal University. Allergy frontier.

“But dogs are now being trained to respond to behavioral and physical cues. Our research shows that at least some dogs can also detect these symptoms through their breathing. I did.”

PTSD is caused by exposure to a catastrophic event. Symptoms include re-experiencing the event, hyperarousal, avoidance of 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 or 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.

Understand scent profiles

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 was an interdisciplinary collaboration between Dr Shelley Stewart's clinical psychology laboratory and Dr Simon Gadbois' canine olfaction laboratory at Dalhousie. “Neither lab could have done this research alone; we brought together two different expertises,” he says Kiiroja.

Scientists recruited 26 people to serve as scent donors. The participants were also taking part in a study about how people react when reminded of trauma they had experienced. 54% met diagnostic requirements for PTSD. To donate scent, they participated in a session in which they recalled 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 the participant while recalling the trauma and provided a target breath sample. Participants also completed questionnaires regarding their stress levels and emotions.

meet the dogs

The scientists also 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 appetite for tasty treats was also an asset. In fact, it was much more difficult to convince them to take a break than to start working. Curry, in particular, made sure that life was not boring. I did.”

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.

Ivy and Laura Kiiroja.

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 believe that Ivy is attuned to hormones in the sympathetic-adrenal-bulbar axis (e.g., adrenaline) and Callie is attuned to hormones in the hypothalamic-pituitary-adrenal axis (e.g., cortisol). This is important knowledge for service dog training and as an early warning.'' The development of PTSD symptoms requires sensitivity to sympatho-adrenal medullary axis hormones. ”

Verification of research results

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.

Curry.