0248 Developmental Differences in the Link Between Sleep Variability and Emotion Regulation During the Preschool Years

Abstract Introduction Sleep plays a central role in supporting emotion regulation (ER) during early childhood (Godzik et al., 2024). Sleep variability – the night-to-night fluctuation in when children go to sleep, how long they sleep, and when they wake – is emerging as a meaningful marker of risk (Hoyniak et al., 2020). A study of school-aged children found that sleep duration and quality were unrelated to self-regulation, but greater variability in sleep onset timing predicted poorer ER and higher impulsivity (Dadzie et al., 2025). Notably, these associations emerged only for certain subgroups, suggesting that the influence of sleep variability may depend on developmental or contextual factors. These associations, however, remain largely unexplored in preschoolers, a period characterized by significant variability in both sleep patterns and emerging ER skills. The present study examined whether night-to-night sleep variability predicts preschoolers’ adaptive and maladaptive ER and whether these associations differ by age. Methods Participants (N = 59) were children aged 3-5 years from a larger study of self-regulation. Sleep variability (average standard deviation of bedtime, time in bed, and total time asleep) was assessed using actigraphy and caregiver-reported sleep diaries. Children’s ER was measured using the Early Emotion Regulation Behavior Questionnaire (EERBQ). Linear regression models tested whether sleep variability separately predicted adaptive and maladaptive ER and whether these associations were moderated by child age. Gender was included as a covariate. Results Results revealed a significant interaction between child age and sleep variability in predicting adaptive ER (β = 0.34, p = .04). Among younger children, greater variability was associated with lower adaptive ER, whereas among older children, greater variability predicted higher adaptive ER. No significant effects emerged for maladaptive ER strategies. Conclusion These findings suggest that sleep variability may affect emotion regulation differently across early childhood. Younger children may struggle to engage in still-developing adaptive ER skills when sleep is irregular, whereas five-year-olds, whose ER abilities are more developed, may be better able to draw on adaptive strategies to cope with poor sleep. Future research should clarify the developmental mechanisms that underlie these age differences and continue to identify which children are most sensitive to sleep variability. Support (if any)