Daily, prospective associations between sleep architecture and affect: insights from Bayesian multilevel...

Emerging statistical methods addressing the multilevel compositional nature of sleep architecture can offer insights into how daily time reallocations between sleep stages (total wake time in bed [TWT], light sleep [Non rapid eye movement stage 1 and 2], slow wave sleep [SWS], and rapid eye movement [REM] sleep) are associated with post-sleep affect.

This study investigated the daily, prospective association between sleep architecture and affect.

In 96 healthy, young adults across 15 consecutive days, sleep architecture was measured at night using electroencephalography (Z-Machine Insight+) and affect was self-reported using the PANAS-X at awakening. Bayesian multilevel compositional data analysis examined how reallocating time between sleep stages was associated with affect.

Various reallocations of sleep stages predicted affect, at both within- and between-person levels. Between-person reallocation of 30 min/night from light or REM sleep to SWS was associated with ≥0.38 points higher high and low arousal positive affect, and from SWS to any other sleep stages was associated with ≥0.21 points higher high arousal negative affect. Within-person reallocation of 30 min/night from REM to any other stages predicted ≥0.05 points higher high arousal negative affect, and 30 min/night from TWT to SWS or REM predicted ≤-0.07 lower low arousal negative affect.

Findings highlight the distinct constellations of sleep architecture associated with affect in everyday life. Extension of SWS and REM for improving affect, while considering other off-set sleep stages, should be confirmed in experimental research in daily settings, to inform diagnostic and intervention strategies for sleep and affective disorders.