Towards an emotional stress test: a reliable, non-subjective cognitive measure of anxious responding.

Response to stress is a key factor in mood and anxiety disorder aetiology. Current measures of stress-response are limited because they largely rely on retrospective self-report. Objectively quantifying individual differences in stress response would be a valuable step towards improving our understanding of disorder vulnerability. Our goal is to develop a reliable, objective, within-subject probe of stress response. To this end, we examined stress-potentiated performance on an inhibitory control task from baseline to 2-4 weeks (n=50) and again after 5-9 months (n=22) as well as examining population measures for a larger sample (n=165). Replicating previous findings, threat of shock improved distractor accuracy and slowed target reaction time on this task. Critically, both within-subject self-report measures of stress (ICC=0.74) and stress-potentiated task performance (ICC=0.58) showed clinically useful test-retest reliability. Threat-potentiated task performance may therefore hold promise as a non-subjective measure of individual stress-reactivity.