How fear and anxiety differ in the prediction of cortisol in graduate firefighters : implications for Revised Reinforcement Sensitivity Theory (R-RST)

Abstract

One suggested explanation for the elevated risk of on-duty death from heart attack in firefighters is an amplified hypothalamic-pituitary-adrenal (HPA) axis response due to the combined physiological and psychological stress load inherent in fire suppression. Although research indicates that cortisol is a factor in the development of atherosclerosis, the influence of specific affective states that contribute to what is commonly accepted as stress (e.g. fear and anxiety) on the release of cortisol is less clear. The revised Reinforcement Sensitivity Theory (r-RST) is a personality model that comprises behavioural systems that clearly delineate between fear (fight, flight and freeze; FFFS) and anxiety (behavioural inhibition system; BIS). Currently, no state r-RST scales exist. The aim of this study is to develop such scales, and use them to explore the relationship between cortisol, fear and anxiety in firefighters during fire suppression. Study 1 uses exploratory and confirmatory factor analysis to develop the new scales, which are demonstrated to have good reliability and internal consistency. Study 2 demonstrates the validity of the scales, in a sample of 16 university students using a memory retrieval protocol. In study 3, the scales are administered to a sample of 12 probationary firefighters, as they performed three evolutions in a live fire training building, with the aim of examining the relationships between cortisol and fear, and cortisol and anxiety. When averaged across the three evolutions, salivary cortisol was shown to be positively related to the FFFS scale, as well as its subscale fight. The relationship between salivary cortisol and the BIS scale was demonstrated to be negative. The findings of this study suggest probationary firefighters experience increased HPA axis activity with increased fear and attenuated anxiety under fire suppression conditions. Researchers using the r-RST to understand personality now have a reliable tool to assess state experience of the r-RST scales. This study also adds to the evidence that fear and anxiety are separate systems and should be treated as so in study design.