Daily Sleep–Stress Reactivity and Functional Impairment in World Trade Center Responders.

This article investigates how individual differences in sleep reactivity to stress (changes in sleep duration and efficiency in response to daily stress) and stress reactivity to sleep (changes in perceived stress following sleep disturbances) predict functional impairment over two years among 9/11 World Trade Center responders. Using ecological momentary assessment data from 452 responders, the study found that greater sleep efficiency reactivity to stress was associated with declines in social and occupational functioning over time, while higher stress reactivity to poor sleep was linked to lower functioning at the initial assessment but not to changes over time. These findings suggest that heightened reactivity in sleep and stress processes may serve as risk factors for deteriorating psychosocial functioning, highlighting the potential value of identifying and targeting high-reactivity individuals in preventative clinical interventions.