Sleep duration and affective reactivity to stressors and positive events in daily life.

Objective: Experimental evidence suggests that inadequate sleep disrupts next-day affective processing and evokes greater stress reactivity. However, less research has focused on whether sleep predicts next-day affective reactivity to naturally occurring stressors and positive events in daily life, as well as the reversed direction of association (i.e., affective reactivity to daily events as predictors of subsequent sleep). The purpose of this study was to evaluate the within-person, bidirectional associations between nightly sleep duration and day-to-day fluctuations in affect related to stressors and positive events. Method: Adults ages 33–84 (N = 1,982, 57% female) in the U.S. National Study of Daily Experiences II reported sociodemographics and chronic conditions at baseline, then completed telephone interviews for 8 consecutive days about their sleep duration, daily stressors, positive events, and affect. Results: Prior-night sleep duration moderated the link between current-day events and positive affect, but not negative affect. Specifically, nights of shorter-than-usual sleep duration predicted more pronounced decreases in positive affect in response to daily stressors, as well as smaller increases in positive affect in response to daily positive events. Results for the reversed direction of association showed no evidence for affective reactivity to daily events as predictors of subsequent sleep duration. People with more chronic conditions were more reactive to positive events, particularly after nights of longer sleep. Conclusion: Affective reactivity to daily stressors and positive events vary based upon sleep duration, such that sleep loss may amplify loss of positive affect on days with stressors, as well as reduce positive affective responsiveness to positive events.