A groundbreaking proof-of-concept study conducted by Laura Kiiroja and colleagues demonstrates that dogs can identify stress-related scents in the breath of individuals with trauma histories, including those diagnosed with post-traumatic stress disorder (PTSD). The research aimed to determine whether dogs could detect volatile organic compounds (VOCs) linked to trauma-induced distress during exposure to personalized trauma cues.
Over the course of 40 sessions, 26 human participants provided breath samples during both calm states and stress-inducing trauma recall. Two scent detection dogs were evaluated using a two-alternative forced choice (2AFC) discrimination task and a yes/no detection task. The dogs achieved approximately 90% accuracy in discriminating between stressed and calm breath samples from the same individual, and 74%–81% accuracy in detecting stressed samples across different individuals.
What makes these results remarkable is that each dog’s performance appeared to align with specific emotional responses reported by human donors. One dog’s accuracy was significantly associated with participants’ self-reported fear, while the other was linked to reported shame. These correlations suggest that dogs may be detecting VOCs derived from different biological stress pathways: the sympathetico-adreno-medullary (SAM) axis and the hypothalamo-pituitary-adrenal (HPA) axis, respectively.
These findings provide an early but crucial step toward refining PTSD service dog training. By identifying specific scent markers tied to different emotional stress states, trainers may eventually teach dogs to reliably detect early signs of psychological distress, enabling preventive intervention or support.
While this study involved a limited sample size and trained facility dogs, it sets a strong precedent for future research into scent-based emotional detection and its therapeutic applications in PTSD and trauma recovery. The implications for enhancing the alert function of service dogs are profound, offering both scientific validation and practical guidance for those working with trauma-experienced individuals.
Source: Laura Kiiroja, S. H. Stewart, and S. Gadbois. 2024-03-28. “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. https://doi.org/10.3389/falgy.2024.1347404
