Blunted cardiac reactivity to psychological stress associated with higher trait anxiety: a study in peacekeepers.

Gabriela Guerra Leal Souza,Eliane Volchan,Nastassja Lopes Fischer,Ivan Figueira,Antônio Fernando Araújo Duarte,Evandro Silva Freire Coutinho,Ana Carolina Ferraz Mendonça-de-Souza,Wanderson Fernandes Souza

doi:10.1186/s12868-015-0216-9

Abstract

BackgroundBoth exaggerated and diminished reactivity to stress can be maladaptive. Previous studies have shown that performing increasingly difficult tasks leads first to increased reactivity and then to a blunted response when success is impossible. Our aim was to investigate the influence of trait anxiety on cardiac and cortisol response to and recovery from a standardized psychosocial stress task (Trier Social Stress Task) in a homogeneous sample of healthy peacekeepers. We hypothesized that participants with higher trait anxiety would show blunted reactivity during the performance of an overwhelmingly difficult and stressful task. Participants (N = 50) delivered a speech and performed an arithmetic task in the presence of critical evaluators. Cortisol samples and electrocardiogram data were collected. Participants completed the State-Trait Anxiety Inventory—Trait version, the Posttraumatic Stress Disorder Checklist—Civilian Version (PCL-C) and the Military Peace Force Stressor Inventory.ResultsFor heart rate, the findings showed that peacekeepers with higher trait anxiety reacted less to the speech task (p = 0.03) and to the arithmetic task (p = 0.008) than those with lower trait anxiety. Trait anxiety did not modulate cortisol responses to the task. Despite the high trait anxiety group having higher PCL-C scores than the low trait anxiety group (p < 0.0001), this did not influence the cardiac results.ConclusionsWe concluded that individuals with higher trait anxiety had less tachycardia in response to acute psychological stress than those with lower trait anxiety. The present results point to a higher risk for more anxious individuals of a maladaptive reaction to stressful events.

Highlights

Both exaggerated and diminished reactivity to stress can be maladaptive
The acute stressor used in the study by Carroll et al [7] was by far one of the most intense stressors in a laboratory setting; in that it was a difficult task performed in the presence of a critical evaluator
When we look for evidence regarding the relationship between trait anxiety and cortisol response to a stressor, a marker of Hypothalamus– pituitary–adrenocortical (HPA)-axis reactivity, the literature does not show a correlation between these two variables

Summary

Introduction

Both exaggerated and diminished reactivity to stress can be maladaptive. Previous studies have shown that performing increasingly difficult tasks leads first to increased reactivity and to a blunted response when success is impossible. We hypothesized that participants with higher trait anxiety would show blunted reactivity during the performance of an overwhelmingly difficult and stressful task. A study investigating the effect of task difficulty on the cardiovascular system revealed that pre-ejection period changes and systolic blood pressure reactivity increased until the task became so difficult that it was impossible to successfully complete. At this exact point, blunted cardiac reactivity was found [21]. It could be hypothesized that highly anxious individuals may consider difficult and stressful tasks to be much more challenging than less anxious individuals do, explaining why Carroll et al [7] found more clearly blunted reactivity in subjects with high levels of anxiety

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