Prospective relations between sleep in preschool years and academic achievement at school entry

Actigraphy-assessed sleep duration and quality and executive function in a sample of typically developing preschoolers

Sleep is essential for cognitive development and brain maturation during early childhood. Studies focused on preschool populations using objective measures of sleep are still scarce. The objective of this study was to examine the associations between objective measures of sleep duration and quality with executive functioning in a 133 non-clinical sample of Spanish participants (Mage = 60.33 months, SD = 9.04; ages 41-77 months; 51.1% girls). Sleep was assessed for five weeknights using actigraphy; Shape School task was applied to assess inhibition and cognitive flexibility; and Word Span task was used to assess working memory. The results revealed that relation between sleep and executive functioning was significant for inhibition and working memory. Preschoolers with higher sleep efficiency showed better results in executive functioning tasks after controlling for the effect of age. Additionally, age and sleep duration and quality variables were predictive of inhibition, working memory, and cognitive flexibility. These results suggest that the different dimensions of sleep could play an important role in the development of executive functions during preschool age. Therefore, improving sleep could lead to an improvement in children's executive functioning in both clinical and educational contexts.

Sleep duration trajectories and cognition in early childhood: A systematic review

Sleep is dynamic in childhood and studies have shown the relationship between sleep and cognition in children. As the human brain is the most plastic during childhood, the study of longitudinal sleep patterns and neurocognition is an important research area. We aimed to systematically review studies that investigated sleep duration trajectories and cognition in typically-developing children. We searched four databases for articles published between 2003 to October 2023. We included observation studies of children with sleep duration trajectories as a predictor and outcomes related to cognition, memory, language, developmental milestones, intelligence or executive function. We excluded studies where children had atypical development or completed the sleep and neurocognitive assessments after six and 12 years of age respectively. Out of 752 articles identified, 511 were screened and 23 full texts were assessed. The selected studies included three single trajectory and four multiple group trajectories studies. We found associations between both types of trajectories and cognitive development. Overall, children with longer sleep trajectories or more mature sleep pattern with rapid decrease in sleep duration, had better performance scores in developmental assessment tools, and intelligence tests. Findings for language and executive functioning were mixed, whereby some studies found associations and others did not.

Association between adverse childhood experiences and sleep quality, emotional and behavioral problems and academic achievement of children and adolescents

The impact of adverse childhood experiences (ACEs) on adult health has been extensively examined, but the association between ACEs and sleep, emotion, behavior and academic outcomes of children and adolescents is not well known. A total of 6363 primary and middle school students were included to examine the effect of ACEs on sleep quality, emotional and behavioral problems and academic achievement and further explore the mediation role of sleep quality and emotional and behavioral problems. Children and adolescents with ACE exposure had 1.37 times risk of poor sleep quality (adjusted odds ratio [OR] = 1.37, 95% confidence interval [CI]: 1.21-1.55), 1.91 times risk of emotional and behavioral problems (adjusted OR = 1.91, 95%CI: 1.69-2.15) and 1.21 times risk of self-reported lower academic achievement (adjusted OR = 1.21, 95%CI: 1.08-1.36). Most types of ACEs were significantly associated with poor sleep quality, emotional and behavioral problems and lower academic achievement. There were dose-response relationships between cumulative ACE exposure and risk of poor sleep quality, emotional and behavioral problems, and lower academic achievement. Sleep quality and emotional and behavioral performance mediated 45.9% of the effect of ACEs exposure on math scores and 15.2% of the effect of ACEs exposure on English scores. Early detection and prevention of ACEs among children and adolescents are urgent and essential, and targeted interventions for sleep and emotional and behavioral performance as well as early educational interventions are recommended for children with ACEs exposure.

Association of early bedtime at 3 years of age with higher academic performance and better non-cognitive skills in elementary school

This study investigated the relationship between sleep habits in early childhood and academic performance and non-cognitive skills in the first grade. We retrospectively analyzed a longitudinal population-based cohort from birth through early childhood, up to elementary school, in Amagasaki City, Japan. The primary outcome was academic performance in the first grade. Other outcomes were self-reported non-cognitive skills. Overall, 4395 children were enrolled. Mean national language scores for children with bedtimes at 18:00-20:00, 21:00, 22:00, and ≥ 23:00 were 71.2 ± 19.7, 69.3 ± 19.4, 68.3 ± 20.1, and 62.5 ± 21.3, respectively. Multiple regression analysis identified bedtime at 3 years as a significant factor associated with academic performance. However, sleep duration was not significantly associated with academic performance. Bedtime at 3 years also affected non-cognitive skills in the first grade. Diligence decreased with a later bedtime (21:00 vs. 18:00-20:00; odds ratio [OR]: 1.98, 95% confidence interval [CI] 1.27-3.09; 22:00 vs. 18:00-20:00; OR: 2.15, 95% CI 1.37-3.38; ≥ 23:00 vs. 18:00-20:00; OR: 2.33, 95% CI 1.29-4.20). Thus, early bedtime at 3 years may be associated with a higher academic performance and better non-cognitive skills in the first grade. Optimum early-childhood sleep habits may positively impact academic future.

From early birds to night owls: a longitudinal study of actigraphy-assessed sleep trajectories during the transition from pre- to early adolescence

STUDY OBJECTIVES

Pre- and early adolescence are believed to constitute periods of important age-related changes in sleep. However, much of the research on these presumed developmental changes has used cross-sectional data or subjective measures of sleep, limiting the quality of the evidence. In addition, little is known about the development of certain features of the sleep-wake cycle pertaining to regularity (e.g. weekend-weekday differences and intra-individual variability) or circadian rhythms (e.g. sleep midpoint).

METHODS

This study examined the sleep trajectories of 128 typically developing youth (69 girls) from ages 8 to 12 years on four sleep characteristics: sleep onset, sleep offset, total sleep time (TST), and sleep midpoint. For each of these characteristics, actigraphy-derived estimates of typical (i.e. mean) sleep and sleep regularity were obtained at each time point. Multilevel growth curves were modeled.

RESULTS

Overall, the sleep-wake cycle significantly changed between 8 and 12 years. Mean sleep onset, offset and midpoint exhibited an ascending curvilinear growth pattern that shifted later with age, while mean TST decreased linearly. Weekend-weekday differences (social jetlag) for sleep offset and midpoint became more pronounced each year. Weekday TST was longer than weekend TST, though this difference became smaller over time. Finally, intra-individual variability increased over time for all sleep characteristics, with variability in TST ascending curvilinearly. Important between-person and sex differences were also observed.

CONCLUSION

This study reveals the marked changes that occur in the sleep of typically developing pre- and early adolescents. We discuss the potential implications of these trajectories.

Nocturnal sleep duration trajectories in early childhood and school performance at age 10 years

Sleep plays a fundamental role in brain development and resultant functions. The aim was to verify whether nocturnal sleep duration during early childhood has long-term associations with academic achievement at age 10 years. The present study is part of the Quebec Longitudinal Study of Child Development, a representative cohort of infants born in 1997-1998 in the province of Quebec, Canada. Children with known neurological conditions were excluded from this cohort. Four trajectories of parent-reported nocturnal sleep duration at ages 2.5, 3, 4, 5 and 6 years were determined using a SAS procedure named PROC TRAJ. Sleep duration at age 10 years was also reported. Teachers provided data on academic performance when the children were age 10 years. These data were available for 910 children (430 boys, 480 girls; 96.6% Caucasians). Univariate and multivariable logistic regressions were performed using SPSS. Children who slept less than 8 hr per night at 2.5 years but normalized later on (Traj1) had three-five times the odds of having grades below the class average in reading, writing, mathematics and science compared with children who slept sufficiently (Traj3-4: 10-11 hr per night). Children who slept about 9 hr per night throughout childhood (Traj2) had two-three times the odds of being below the class average in mathematics and science. Sleep duration at age 10 years was not correlated with the academic performance. These results point to the presence of a very important early period during which sufficient sleep is needed to fine-tune the functions necessary for academic achievement later on.

Associations Between Preschool Sleep Problems and Observed Dimensions of Elementary Classroom Engagement

Sleep has clear importance for academic success. However, most research in this area has focused on older children and adolescents and has used narrow measures of academic achievement, overlooking the importance of early sleep problems in shaping children's classroom behaviors that support academic success. Using a community sample (N = 276, 50% female), the current study examined associations between parent-reported preschool sleep problems (M _age = 3.84, SD = 0.83) and three dimensions of classroom engagement coded during live classroom observations in the first grade (M _age = 6.72, SD = 0.34). The moderating role of family socioeconomic status (SES) was also considered. A multivariate multilevel model found that more preschool sleep problems were associated with less focused engagement (defined as involvement in academic tasks, such as writing or asking questions), but more competing responses (defined as inappropriate or distracting behaviors). Preschool sleep problems were not associated with task management (defined as preparation for academic tasks, such as locating classroom materials). Although family SES did not moderate any of these associations, higher income-to-needs ratios in preschool were associated with more focused engagement and fewer competing responses. Findings highlight the role of early sleep problems in classroom behaviors that facilitate academic success. Targeting sleep problems prior to the school transition may serve as a useful approach to optimizing learning conditions during this key developmental period.