Salivary measures of stress and immunity in police officers engaged in simulated critical incident scenarios

OBJECTIVE:: This research investigated the effects of a critical incident lethal force scenario on a panel of salivary biomarkers, measured at baseline and then at 10 and 30 minutes postscenario, in 141 law enforcement volunteer officers. METHODS:: Officers were randomly assigned to two virtual reality scenarios. One scenario was brief and involved a police officer chasing a suspect on a motorcycle, confronting the suspect who draws a gun and shoots the police officer. The other scenario involved a lengthy chase by the police officer through a workplace of an armed perpetrator ultimately engaging in gunfire with the police officer. Saliva was analyzed for cortisol, secretory immunoglobulin A (sIgA), interleukin-6, and alpha-amylase concentrations. RESULTS:: The "workplace" scenario produced the largest responses in biomarkers, with significant rises in cortisol, interleukin-6, alpha-amylase, and secretory immunoglobulin A. These data suggest that virtual reality can produce stress and immune effects. CONCLUSIONS:: This research suggests that virtual reality scenarios produce physiologic stress responses, mimicking occupational stress.