Day-to-day directional relationships between sleep duration and negative affect

Area of Science:

• Psychology
• Sleep Science
• Affective Science

Background:

• A strong association exists between sleep disturbance and negative affect.
• The precise day-to-day directional relationship between sleep and negative affect requires further clarification.

Purpose of the Study:

• To investigate the bidirectional, day-to-day associations between sleep duration and negative affect in community-dwelling adults.
• To determine if sleep duration predicts subsequent negative affect, or if negative affect predicts subsequent sleep duration.

Main Methods:

• Utilized two subsamples from the Midlife in the United States Study (N=2,022 and N=782).
• Assessed daily negative affect and previous night's sleep duration via telephone interviews over eight days.
• Employed random intercept cross-lagged panel models to analyze directional effects, controlling for covariates.

Main Results:

• Shorter sleep duration significantly predicted higher next-day negative affect in both samples.
• Negative affect did not significantly predict subsequent sleep duration.
• The relationship between sleep duration and negative affect was nonlinear.

Conclusions:

• Sleep duration unidirectionally predicts next-day negative affect in adults.
• An optimal sleep duration range of 7.5 to 10.5 hours was associated with the lowest levels of next-day negative affect.
• Deviations below 7.5 or above 10.5 hours of sleep were linked to increased negative affect.