Relationship between salivary neuropeptide Y and performance under stress: a study on police firearms officers

Introduction An emerging body of evidence suggests that plasma neuropeptide Y (NPY) concentration is positively associated with performance under conditions of psychological stress. However, whether NPY concentrations in saliva are associated with performance under stress remains unknown. Methods We collected saliva samples in a high-performance environment and tested the associations between salivary NPY, self-reported psychological variables, and performance during a stressful task. Participants were 15 male police firearms officers (M age = 33.57 years, SD = 3.92) enrolled in a demanding selection course. Participants provided their saliva samples using the passive drool method 1 h before the shooting task, which they needed to pass to remain on the course (high-stress condition). Additionally, they provided a sample on a low-stress training day (low-stress condition). Self-reported measures of psychological state included measures of state anxiety (cognitive and somatic), self-confidence, and threat appraisals provided 1 h prior to the shooting task. Results and discussion NPY concentrations were detected under both high- and low-stress conditions. Mean NPY levels (ng/mL) were higher before the high-stress shooting task ( M = 1.56, SD = 0.88) than on the low-stress training day ( M = 1.13, SD = 0.52), but this difference did not reach significance. Salivary NPY concentrations prior to the shooting task were positively and strongly associated with shooting performance ( n = 13, r = 0.71, p = 0.007). There were no associations between psychological variables and salivary NPY or shooting performance. This study provides an important initial step in exploring the salivary NPY–performance relationship. Further studies are needed to determine whether these results can be replicated across different performance tasks and domains.