Post-traumatic stress disorder (PTSD) is a prevalent mental health condition, and service dogs are increasingly used as part of therapeutic support. However, their effectiveness depends on understanding the biological cues dogs respond to. In a novel study, Kiiroja et al. (2024) tested whether dogs could detect volatile organic compounds (VOCs) released during stress episodes in trauma survivors.
Breath samples were collected from 26 participants, 54% of whom had PTSD, during calm states and after exposure to personalized trauma cues. Two trained scent-detection dogs were tasked with distinguishing between control and stress samples. In discrimination tests, the dogs achieved an impressive ~90% accuracy, while detection tests across individuals yielded 74% and 81% accuracy.
Interestingly, analysis revealed that each dog’s detection performance correlated with different emotional responses. One dog’s accuracy aligned with participants’ self-reported fear responses, suggesting sensitivity to markers of the sympathetico-adreno-medullary (SAM) axis such as adrenaline. The other dog’s performance correlated with shame responses, suggesting sensitivity to hypothalamo-pituitary-adrenal (HPA) axis markers like glucocorticoids.
This study provides the first scientific evidence that dogs can detect stress-related VOCs in trauma survivors’ breath, highlighting the role of olfaction in human–dog interactions. The findings may inform PTSD service dog training protocols, helping tailor alert behaviors to specific physiological stress markers and improving support for individuals with trauma histories.
Source: Kiiroja, L., Stewart, S. H., & Gadbois, S. (2024). Can scent-detection dogs detect the stress associated with trauma cue exposure in people with trauma histories? A proof-of-concept study. Frontiers in Allergy, 5.
