Effects of school start time on students' sleep duration, daytime sleepiness, and attendance: a meta-analysis

A systematic and meta-analytic review of the impact of sleep restriction on memory formation

Modern life causes a quarter of adults and half of teenagers to sleep for less than is recommended (Kocevska et al., 2021). Given well-documented benefits of sleep on memory, we must understand the cognitive costs of short sleep. We analysed 125 sleep restriction effect sizes from 39 reports involving 1234 participants. Restricting sleep (3-6.5 hours) compared to normal sleep (7-11 hours) negatively affects memory formation with a small effect size (Hedges' g = 0.29, 95 % CI = [0.13, 0.44]). We detected no evidence for publication bias. When sleep restriction effect sizes were compared with 185 sleep deprivation effect sizes (Newbury et al., 2021) no statistically significant difference was found, suggesting that missing some sleep has similar consequences for memory as not sleeping at all. When the analysis was restricted to post-encoding, rather than pre-encoding, sleep loss, sleep deprivation was associated with larger memory impairment than restriction. Our findings are best accounted for by the sequential hypothesis which emphasises complementary roles of slow-wave sleep and REM sleep for memory.

Association Between Sleep Hygiene Parameters and Sleep Habits in 5- to 10-Year-Old School-Age Children

Insufficient sleep can lead to problems. We examined the sociodemographic characteristics, sleep habits, and association between sleep problems. Parents were requested to fill out a survey and Children's Sleep Habits Questionnaire (CSHQ). The mean age of 1226 students was 8.42 (5.0-10.0) years. A total of 50.7% were male students. In addition, 69.1% showed signs of sleep problems in the CSHQ. In multivariate logistic regression analysis, bed-sharing, owning cell phone, attending early education group, not using toilet before bedtime, television watching duration, being an only child, not doing physical activity, watching TV before bed on weekends, caffeinated beverage consumption, not reading a book before sleep, waking up at night, sleeping in lighted rooms, maternal education level, having 1 sibling, and not having tablet variables were statistically significant in causing sleep problems. Poor sleep habits and sleep hygiene problems are common in school-age children. Healthy sleep habits are essential to get adequate and quality sleep.

Do later school start times improve adolescents' sleep and substance use? A quasi-experimental study

OBJECTIVE

A later school start time policy has been recommended as a solution to adolescents' sleep deprivation. We estimated the impacts of later school start times on adolescents' sleep and substance use by leveraging a quasi-experiment in which school start time was delayed in some regions in South Korea.

METHODS

A later school start time policy was implemented in 2014 and 2015, which delayed school start times by approximately 30-90 minutes. We applied difference-in-differences and event-study designs to longitudinal data on a nationally representative cohort of adolescents from 2010 to 2015, which annually tracked sleep and substance use of 1133 adolescents from grade 7 through grade 12.

RESULTS

The adoption of a later school start time policy was initially associated with a 19-minute increase in sleep duration (95% CI, 5.52 to 32.04), driven by a delayed wake time and consistent bedtime. The policy was also associated with statistically significant reductions in monthly smoking and drinking frequencies. However, approximately a year after implementation, the observed increase in sleep duration shrank to 7  minutes (95% CI, -12.60 to 25.86) and became statistically nonsignificant. Similarly, the observed reduction in smoking and drinking was attenuated a year after.

CONCLUSIONS

Our findings suggest that policies that increase sleep in adolescents may have positive effects on health behaviors, but additional efforts may be required to sustain positive impacts over time. Physicians and education and health policymakers should consider the long-term effects of later school start times on adolescent health and well-being.

Effects of school start time and its interaction with the solar clock on adolescents' chronotype and sleep: A systematic review and meta-analysis

Adolescents' late chronotypes colliding with early school start times (SSTs) are associated with students' unhealthy sleep habits. Most studies comparing different SSTs associate later SSTs with longer sleep duration and lower social jetlag. However, the magnitude of the effect varies between studies and the effect of different SSTs on chronotype is not well established. Importantly, although human circadian rhythms are entrained by sunlight, when studying the effect of different SSTs on adolescents' sleep habits usually only the social clock, and not the solar clock, is considered. This meta-analysis investigates whether later SSTs affect adolescents' sleep habits and chronotype and it assesses factors that can modulate this effect, including the relative importance of social and solar clocks. Here, through a database search we identify 37 studies comparing the effect of different SSTs on adolescents' sleep habits and/or chronotype. Random effect meta-analyses showed that later SSTs are associated with later sleep timings and longer sleep duration on weekdays, lower levels of social jetlag, and later chronotypes. Several meta-regressions reveal that the distance between compared SSTs and the interplay between SSTs and the solar clock modulate the effect of different SSTs on sleep timings and duration on weekdays.

The Impact of the Double School Shift System on Lifestyle Behaviors Among Mexican Adolescents

PURPOSE

Early school start times could adversely impact adolescent sleep duration. They could also impact other behaviors like diet and physical activity, either directly or indirectly through effects on sleep. We examined whether the double school shift system was associated with sleep, diet, and physical activity behaviors among Mexican adolescents.

METHODS

The analytic sample included 305 Mexican adolescents from a cohort study (on average 14.53 ± 1.75 years old and 51% male). Sleep and physical activity were measured with wrist actigraphy, while diet and other lifestyle behaviors were assessed with questionnaires. Regression analyses were conducted to compare lifestyle behaviors between the morning and afternoon school shifts, adjusting for potential confounders.

RESULTS

Adolescents attending the morning school shift (44%) had pronounced differences in sleep compared to those attending afternoon shift, including a 1.77-hour shorter sleep duration on weekdays (95% CI -1.55, -2.00), a 0.40-hour longer sleep duration on weekends (95% CI 0.10, 0.70), higher social jetlag (1.07 hours with a 95% CI of 0.87, 1.27), and an earlier chronotype. Morning shift students also had 0.85 hours longer sedentary time (95% CI 0.61, 1.10) and higher consumption of a meat and starchy food dietary pattern. Among boys only, morning shift was associated with a lower likelihood of smoking and higher consumption of a breakfast pattern.

DISCUSSION

Overall, attending a morning school shift was associated with shorter sleep, more social jetlag, greater sedentary time, and higher consumption of a meat and starchy diet. However, among boys, a few healthier behaviors were observed for the morning versus afternoon shift.

Delayed bedtime on non-school days associates with higher weight and waist circumference in children: Cross-sectional and longitudinal analyses with Mendelian randomisation

Sleep duration has been linked with obesity in population-based studies. Less is known about bedtimes and, especially, if discrepancy between bedtimes on school and non-school days associate with adiposity in children. The associations of self-reported bedtimes with the body mass index z-score (BMIz) and waist-to-height ratio (WtHr) were examined among children with a mean (SD) age of 11.2 (0.85) years in cross-sectional (n = 10,245) and longitudinal (n = 5085) study settings. The causal relationship of whether BMIz contributes to bedtimes, was further examined in a subset of 1064 participants by exploiting Mendelian randomisation (MR). After adjusting for sleep duration and other confounders, every 0.5 h later bedtime on non-school nights and a delay in bedtime in non-school nights compared with school nights associated with 0.048 (95% CI 0.027; 0.069) and 0.08 (95% CI 0.056; 0.105) higher BMIz as well as 0.001 (95% CI 0; 0.002) and 0.004 (95% CI 0.003; 0.005) with higher WtHr, respectively. Moreover, every 0.5-h delay in bedtime in non-school nights compared with school nights associated with 0.001 (95% CI 0; 0.002) greater increase in WtHr in the 2.5 years follow-up. Thus, a 2-h delay in bedtime at the age of 11 years corresponds with a 0.6 cm increase in waist circumference. The MR analysis did not indicate an opposite causal relationship: higher BMIz was not causing delayed bedtimes. Later bedtime on non-school days and discrepancy in bedtimes associated with increased BMIz and WtHr, while longitudinally these predicted higher WtHr, independently of sleep duration. Promoting early bedtimes, especially on weekends, should be considered in obesity prevention among school-aged children.

Solar clock and school start time effects on adolescents' chronotype and sleep: A review of a gap in the literature

Circadian rhythms are entrained by external factors such as sunlight and social cues, but also depend on internal factors such as age. Adolescents exhibit late chronotypes, but worldwide school starts early in the morning leading to unhealthy sleep habits. Several studies reported that adolescents benefit from later school start times. However, the effect of later school start time on different outcomes varies between studies, and most previous literature only takes into consideration the social clock (i.e. local time of school starting time) but not the solar clock (e.g. the distance between school start time and sunrise). Thus, there is an important gap in the literature: when assessing the effect of a school start time on chronotype and sleep of adolescents at different locations and/or seasons, the solar clock might differ and, consistently, the obtained results. For example, the earliest school start time for adolescents has been suggested to be 08:30 hours, but this school start time might correspond to different solar times at different times of the year, longitudes and latitudes. Here, we describe the available literature comparing different school start times, considering important factors such as geographic position, nationality, and the local school start time and its distance to sunrise. Then, we described and contrasted the relative role of both social and solar clocks on the chronotype and sleep of adolescents. As a whole, we point and discuss a gap in literature, suggesting that both clocks are relevant when addressing the effect of school start time on adolescents' chronotype and sleep.

[Overview of chronobiological and sleep medical aspects of depression in adolescents]

Changes in sleep are reported in adolescents with depression with a frequency of up to 71%. Aspects of chronobiology and sleep based on the current scientific literature are illustrated and summarized in this narrative review. The circadian clock synchronizes organisms to the light-dark structure of the environment. The individual synchronization is called "chronotype." Chronotype changes according to age, among other factors, and adolescents experience the latest chronotypes overall. The potential discrepancy between internal and external time is called "social jetlag." Social jetlag is especially pronounced during adolescence. It is associated with numerous health risks, such as depression. Changes in sleep behavior in affective disorders and its comorbidity to depression have also been well described in the literature. In this article, underlying concepts from chronobiology and sleep medicine are initially summarized. Then, health risks of disrupted sleep-wake behavior are described, and connections to depression specifically during adolescence are drawn. The article concludes with clinical recommendations for sleep disorders and depression during adolescence as well as suggestions for further research.

The associations between instructional approach, sleep characteristics and adolescent mental health: Lessons from the COVID-19 pandemic

OBJECTIVES

To test whether adolescents' mental health during the COVID-19 pandemic is associated with the combination of their instructional approach(es) and their sleep patterns.

DESIGN

Cross-sectional.

SETTING

Adolescents were recruited through social media outlets in October and November 2020 to complete an online survey.

PARTICIPANTS

Participants were 4442 geographically and racially diverse, community-dwelling students (grades 6-12, 51% female, 36% non-White, 87% high schoolers).

MEASUREMENTS

Participants completed items from the PROMIS Pediatric Depressive Symptoms and Anxiety scales. Participants reported their instructional approach(es), bedtimes, and wake times for each day in the past week. Participants were categorized into five combined instructional approach groups. Average sleep opportunity was calculated as the average time between bedtime and waketime. Social jetlag was calculated as the difference between the average sleep midpoint preceding non-scheduled and scheduled days.

RESULTS

Emotional distress was elevated in this sample, with a large proportion of adolescents reporting moderate-severe (T-score ≥ 65) levels of depressive symptoms (49%) and anxiety (28%). There were significant differences between instructional approach groups, such that adolescents attending all schooldays in-person reported the lowest depressive symptom and anxiety T-scores (P < .001, ηp2 = .012), but also the shortest sleep opportunity (P < .001, ηp2 = .077) and greatest social jetlag (P < .001, ηp2 = .037) of all groups. Adolescents attending school in person, with sufficient sleep opportunity (≥8-9 hours/night) and limited social jetlag (<2 hours) had significantly lower depressive (ηp2 = .014) and anxiety (ηp2 = .008) T-scores than other adolescents.

CONCLUSIONS

Prioritizing in-person education and promoting healthy sleep patterns (more sleep opportunity, more consistent sleep schedules) may help bolster adolescent mental health.

Sleep behavioral outcomes of school-based interventions for promoting sleep health in children and adolescents aged 5 to 18 years: a systematic review

Study Objectives

Insufficient sleep is common among children and adolescents, and can contribute to poor health. School-based interventions potentially could improve sleep behavior due to their broad reach, but their effectiveness is unclear. This systematic review focused on the effects of school-based interventions on sleep behavior among children and adolescents aged 5 to 18 years.

Methods

Five electronic databases were searched for randomized controlled trials of sleep health interventions initiated or conducted in school settings and in which behavioral sleep outcomes were measured. Cochrane risk of bias tools were used to assess study quality.

Results

From the 5303 database records and two papers from other sources, 21 studies (22 papers) met the inclusion criteria for this review. These studies involved 10 867 children and adolescents at baseline from 13 countries. Most studies (n = 15) were conducted in secondary schools. Sleep education was the most common intervention, either alone (n = 13 studies) or combined with other initiatives (stress management training, n = 2; bright light therapy, n = 1; health education, n = 1). Interventions were typically brief in terms of both the intervention period (median = 4 weeks) and exposure (median = 200 minutes). Behavioral outcomes included actigraphy-measured and self-reported sleep patterns, and sleep hygiene. All outcomes had high risk of bias or some concerns with bias. Sleep education interventions were typically ineffective. Later school start times promoted longer sleep duration over 1 week (1 study, high risk of bias).

Conclusions

Current evidence does not provide school-based solutions for improving sleep health, perhaps highlighting a need for complex, multi-component interventions (e.g. whole-of-school approaches) to be trialed.

Mediating roles of sleep quality and resilience in the relationships between chronotypes and mental health symptoms

Sleep and mental health are intrinsically intertwined, but not every individual with problems sleeping develops a mental health disorder. This study examined the association among chronotypes, resilience, sleep quality and mental health symptoms amongst otherwise healthy individuals. Two hundred adults (Mage = 27.75 ± 5.11, 68% female) with no previous diagnosis of mental illness were recruited and filled in a set of questionnaires measuring chronotypes, sleep quality, depression and anxiety symptoms. The findings from the path analysis showed that the morning type had a statistically significant direct effect on a range of sleep quality indices. These included better subjective sleep quality, shortened sleep latency, and fewer daytime dysfunctions, as well as a higher level of resilience. However, it did not significantly affect depression and anxiety symptoms. In addition, the morning type had statistically significant indirect effects on a higher level of resilience and fewer depression and anxiety symptoms through the mediating effect of sleep quality indices. Findings from this study support that morning type is associated with better resilience and psychological health, which is mediated through better sleep quality.

Affiliative Parent-Adolescent Bedtime and Waketime Interactions are Associated with Adolescent Sleep

OBJECTIVES

The current study examined whether evening and morning affiliation (i.e., warmth) and autonomy (i.e., more or less in charge) around sleep routines predicted adolescent sleep on weekdays.

METHOD

Participants were 28 parent (Mage = 43.19; 85.17% mothers) and adolescent (Mage = 12.34 years) dyads who completed the same electronic diaries morning and evening for 10 days, with a total number of 221 nights observed across dyads. Sleep duration and sleep quality were assessed via the Pittsburgh Sleep Diary; degree of affiliation and autonomy around bedtime and waketime routines were assessed with single items on a visual analog scale. Multilevel modeling was utilized to evaluate the effects of more or less affiliation or autonomy on sleep outcomes (i.e., duration and quality) between and within dyads.

RESULTS

Across all participants, adolescents who reported more affiliative interactions with their parent around bedtime and waketime slept longer and had better sleep quality at night. Further, when adolescents experienced greater than average affiliative interactions with their parent than was typical for them, they had better sleep quality that night. Adolescent sleep quality and duration were not impacted by whether or not adolescents were in charge of their bedtime and waketime routines.

CONCLUSIONS

Findings support parents' role in social and emotional security and highlight the importance of affiliative parent interactions around the sleep period for optimal sleep for young adolescents.

Before-school physical activity levels and sociodemographic correlates among Australian adolescents: A cross-sectional study

Understanding adolescents' physical activity levels and underpinning contextual factors is crucial for health promotion. This cross-sectional study, using 24-hour time use diaries and sociodemographic variables from the Longitudinal Study of Australian Children, addressed gaps in understanding of physical activity in the before-school segment (the time between waking up and commencing classes). The study examined a) adolescents' time spent in before-school physical activity, focusing on location and shared presence, and b) sociodemographic correlates of before-school physical activity. Completed diaries by 12-13 year-olds (n = 3,201) revealed that adolescents reported an average of 10.8 minutes of daily before-school physical activity (average segment length: 114 min), mostly classified as active transport (5.7 min). Most before-school physical activity occurred in a location other than home or school (6.1 min) and with peers (6.1 min). Notably, 51% of boys and 60% of girls did not report any before-school physical activity. Through two-part regression, we found that boys, adolescents from single-parent households, and those with longer before-school segments are more likely to report before-school physical activity compared to their counterparts. Before-school initiatives should promote active transport and diverse opportunities in other settings. Research into barriers and facilitators may inform more inclusive and effective promotion strategies, including school-based initiatives.

Childhood sleep: assessments, risk factors, and potential mechanisms

BACKGROUND

Sleep problem is a highly prevalent health issue among pediatric populations across the world. In this review, we aimed to identify risk factors contributing to sleep deficiency and poor sleep hygiene in children. Potential biological, psychosocial, and environmental mechanisms as well as research gaps in the literature are also discussed.

DATA SOURCES

A comprehensive search for relevant English language full-text, peer-reviewed publications was performed focusing on pediatric sleep studies from prenatal to childhood and adolescence in a variety of indexes in PubMed, SCOPUS, and Psych Info. Both relevant data based and systematic reviews are included.

RESULTS

This paper summarizes many risk factors for childhood sleep problems, including biological (e.g., genetics, gender, age and puberty, prenatal factors, postnatal factors); nutritional (e.g., macronutrients, micronutrients, omega-3 fatty acids, obesity); environmental (e.g., heavy metals, noise, light, air pollution); interpersonal (e.g., family, exposure to violence, screen media use, physical injury); and community/socioeconomic variables (e.g., racial/ethnicity and cultural factors, neighborhood conditions and socioeconomic status, school factors, public health disasters/emergencies), to better understand the development of sleep problems in children.

CONCLUSIONS

Poor childhood sleep is a multifactorial issue affected by a wide range of prenatal and early-life biological, environmental, and psychosocial risk factors and contributors. A better understanding of these risk factors and their mechanisms is an important first step to develop future research and prevention programs focusing on pediatric sleep problems.

Short Sleep Duration in School-Age Children: Differential Factors on Weekdays and Weekends

OBJECTIVES

To quantify school-age children's sleep and parent-associated factors on weekdays and weekends in Singapore, and investigate school-related and parent-related factors associated with short sleep.

METHODS

In an online survey, 251 parents with a child aged 7-12 y in Singapore reported their child's sleep duration and school start time. Parent-related factors including sleep hygiene (e.g., parent-set bedtime), sleep priority (the amount of sleep respondents allowed their children to trade for other activities), and both parents' sleep durations, were also reported.

RESULTS

The prevalence of short sleep among the children was 64.5% on weekdays and 19.5% on weekends. Children's sleep duration increased from 8.42 h on weekdays to 9.45 h on weekends (p < .001). Relative to weekdays, on weekends, parents showed similar increases in sleep durations (p < .001), imposed poorer sleep hygiene on their children (reduced likelihood of setting bedtimes and increased pre-bedtime electronic device use; p < .001), and allowed their children to trade more sleep for interacting with family and friends, social media, gaming, and TV / videos (p < .001). Shorter sleep duration in children was significantly associated with earlier school start time (B = 0.80, p = .02) and poorer sleep hygiene on weekdays (B = 0.16, p < .001), but lower sleep priority (B = 0.05, p = .002) and shorter parental sleep duration on weekends (maternal: B = 0.18, p < .001, paternal: B = 0.17, p = .002).

CONCLUSIONS

Delaying school start times may be effective in increasing school-age children's sleep duration on weekdays, while family-based interventions designed to enhance sleep hygiene, priority of sleep over other activities, and parents' sleep durations can benefit children's sleep duration on both weekdays and weekends.

Adverse childhood experiences, sleep problems, low self-control, and adolescent delinquency: A longitudinal serial mediation analysis

Several studies link adverse childhood experiences (ACEs) to delinquency. Yet, developmental sequalae accounting for this association remain unclear, with previous research limited by cross-sectional research designs and investigations of singular mediating processes. To redress these shortcomings, this study examines the longitudinal association between ACEs and delinquency as mediated by both sleep problems and low self-control, two factors which past research implicates as potentially important for understanding how ACEs contribute to antisocial behavior. Data collected from 480 adolescents (71.3% boys; 86.3% White) and their parents participating in the Michigan Longitudinal Study was used to conduct a serial mediation analysis. The association between ACEs (prior to age 11) and delinquency in late adolescence was found to operate indirectly via sleep problems in early adolescence and low self-control in middle adolescence. Nonetheless, a direct association between ACEs and later delinquency remained. Pathways through which ACEs contribute to later delinquency are complex and multiply determined. Findings indicate that early behavioral interventions, including improving sleep and self-control, could reduce later delinquency. Still, more research is needed to identify additional avenues through which the ACEs-delinquency association unfolds across development.

Disparities in Sleep-Disordered Breathing: Upstream Risk Factors, Mechanisms, and Implications

Sleep-disordered breathing (SDB) refers to a spectrum of disorders ranging from habitual snoring without frank episodes of obstructed breathing or desaturation during sleep to obstructive sleep apnea, where apneas and hypopneas repetitively occur with resultant intermittent hypoxia, arousal, and sleep disruption. Disparities in SDB reflect its overall high prevalence in children and adults from racially and ethnically minoritized or low socioeconomic status backgrounds coupled with high rates of underdiagnosis and suboptimal treatment.

Impact of delaying high school start times on weight and related behaviors - the START study

In the US, few adolescents get adequate school night sleep, largely due to early school start times. In the START study we aimed to test the following hypothesis: That following the implementation of later high school start times students have lesser longitudinal increases in body mass index (BMI) and shift to more healthful weight-related behaviors relative to students attending schools that retain early start times. The study enrolled a cohort of students (n = 2426) in five high schools in the Twin Cities, MN metro. Heights and weights were measured objectively, and surveys were administered annually from 9th through 11th grades (2016-2018). All study schools started early (either 7:30 am or 7:45 am) at baseline (2016). At follow-up 1 (2017) and continuing through follow-up 2 (2018), two schools delayed their start times by 50-65 min, while three comparison schools started at 7:30 am throughout the observation period. Using a difference-in-differences natural experiment design, we estimated differences in changes in BMI and weight-related behaviors over time between policy change and comparison schools. Students' BMIs increased in parallel in both policy change and comparison schools over time. However relative to changes in comparison schools after the start time shift, students in policy change schools had a modestly more healthful profile of weight-related behaviors - for instance they had a relatively greater probability of eating breakfast, having supper with their family, getting more activity, eating fast food less frequently, and eating vegetables daily. Later start times could be a durable, population-wide strategy that promotes healthful weight behaviors.

School start time delays and high school educational outcomes: Evidence from the START/LEARN study

INTRODUCTION

Delaying high school start times extends adolescents' nightly sleep, but it is less clear how it affects educational outcomes. We expect links between school start time delays and academic performance because getting enough sleep is a key input to the cognitive, health, and behavioral factors necessary for educational success. Thus, we evaluated how educational outcomes changed in the 2 years following a school start time delay.

METHODS

We analyzed 2153 adolescents (51% male, 49% female; mean age 15 at baseline) from START/LEARN, a cohort study of high school students in the Minneapolis-St. Paul, MN, USA metropolitan area. Adolescents experienced either a school start time delay ("policy change schools") or consistently early school start times ("comparison schools"). We compared patterns of late arrivals, absences, behavior referrals, and grade point average (GPA) 1 year before (baseline, 2015-2016) and 2 years after (follow-up 1, 2016-2017 and follow-up 2, 2017-2018) the policy change using a difference-in-differences analysis.

RESULTS

A school start time delay of 50-65 min led to three fewer late arrivals, one fewer absence, a 14% lower probability of behavior referral, and 0.07-0.17 higher GPA in policy change schools versus comparison schools. Effects were larger in the 2nd year of follow-up than in the 1st year of follow-up, and differences in absences and GPA emerged in the second year of follow-up only.

CONCLUSIONS

Delaying high school start times is a promising policy intervention not only for improving sleep and health but for improving adolescents' performance in school.

Santos I, Matijasevich A, Tovo-Rodrigues L. Sleep Duration in Adolescence and Its Prenatal, Perinatal, and Health Determinants in a Large Population-based Cohort Followed from Birth

Objective  To investigate sleep duration and its associated factors in adolescents aged 11 years from the 2004 Pelotas (Brazil) Birth Cohort Study. Methods  Sleep duration was assessed using a self-report sleep habits. Independent variables included perinatal, sociodemographic, behavioral, and health characteristics. The associations were estimated using multiple linear regression. Results  The mean sleep duration of 3,179 adolescents was 9.3 hour (SD =1.7 hour). Longer sleep duration was associated with lower socioeconomic status at birth (β: 0.37, 95% CI: 0.12; 0.61), lower mother's education level ( p  < 0.001), and being female (β: 0.19, 95% CI: 0.06; 0.33). Shorter sleep duration was associated with cesarean section delivery (β: -0.16, 95% CI: -0.31; -0.02); having classes in the morning shift (β: -1.38, 95% CI: -1.51; -1.26), and lower terciles of physical activity ( p  = 0.04). Conclusions  The mean sleep duration observed in this study was consistent with the international recommendations for this age range. Adolescents from lower income families, who are more active, study in shifts other than morning, girls, and those born through vaginal delivery presented higher sleep duration than their counterparts.

The impact of delayed school start time on adolescent beverage consumption, findings from the START study

OBJECTIVES

We sought to examine the effects of high school start time delay, a proven sleep-promoting intervention, on sugary beverage (SB) consumption among U.S. adolescents.

METHODS

In the Spring of 2016 (baseline), the START study recruited 2134 ninth grade students who were enrolled high schools in the Twin Cities, MN metropolitan area. These participants were surveyed again in their 10th and 11th grade years, in Spring 2017 and 2018 (follow-ups 1 and 2). All five high schools started early (7:30 or 7:45 a.m.) at baseline. By follow-up 1, two "policy change" schools shifted their start times later (8:20 or 8:50 a.m.) and maintained these later start times through follow-up 2 while three "comparison schools" retained an early start time at all time points. Generalized estimating equations using a negative binomial distribution were used to obtain estimates of the number of sugary beverages consumed per day at each wave as well as the difference in difference (DiD) estimates between baseline and each follow-up period comparing policy change to comparison schools.

RESULTS

Mean baseline sugary beverage consumption was 0.9 (1.5) beverages per day in policy change schools and 1.2 (1.7) beverages per day in the comparison schools. While there was no evidence of impact of start time change on total SB consumption, DiD estimates revealed a small decrease in the number of caffeinated sugary beverages consumed between baseline and the second follow-up period in students attending the policy change schools relative to comparison schools in both crude (0.11/day reduction, p-value = 0.048) and adjusted analyses (0.11/day reduction, p-value = 0.028).

CONCLUSION

Although the differences in this study were quite modest, a population-wide reduction in sugary beverage consumption could have public health benefit.

Early morning university classes are associated with impaired sleep and academic performance

Attending classes and sleeping well are important for students' academic success. Here, we tested whether early morning classes are associated with lower attendance, shorter sleep and poorer academic achievement by analysing university students' digital traces. Wi-Fi connection logs in 23,391 students revealed that lecture attendance was about ten percentage points lower for classes at 08:00 compared with later start times. Diurnal patterns of Learning Management System logins in 39,458 students and actigraphy data in 181 students demonstrated that nocturnal sleep was an hour shorter for early classes because students woke up earlier than usual. Analyses of grades in 33,818 students showed that the number of days per week they had morning classes was negatively correlated with grade point average. These findings suggest concerning associations between early morning classes and learning outcomes.

Social jetlag and quality of life among nursing students during the COVID-19 pandemic: a cross-sectional study

BACKGROUND

Amid drastic changes in the educational environment and continued substitution of in-person learning with online learning owing to the COVID-19 pandemic, it is important to analyze the predictors of quality of life among nursing students to devise strategies to enhance their quality of life. This study aimed to identify the predictors of nursing students' quality of life during the COVID-19 pandemic, focusing on social jetlag.

METHODS

In this cross-sectional study, data were collected from 198 Korean nursing students in 2021, using an online survey. Chronotype, social jetlag, depression symptoms, and quality of life were assessed using the Korean version of the Morningness-Eveningness Questionnaire, Munich Chronotype Questionnaire, Center for Epidemiological Studies Depression Scale, and World Health Organization Quality of Life Scale abbreviated version, respectively. Multiple regression analyses were performed to identify the predictors of quality of life.

RESULTS

Factors affecting participants' quality of life were age (β = - 0.19, p = .003), subjective health status (β = 0.21, p = .001), social jetlag (β = - 0.17, p = .013), and depression symptoms (β = - 0.33, p < .001). These variables accounted for 27.8% of the variance in quality of life.

CONCLUSION

As the COVID-19 pandemic continues, the social jetlag of nursing students has decreased compared to before the pandemic. Nevertheless, the results showed that mental health issues such as depression affect their quality of life. Therefore, it is necessary to devise strategies to support students' ability to adapt to the rapidly changing educational environment and promote their mental and physical health.

Later school start time is associated with longer school day sleep duration and less social jetlag among Norwegian high school students: Results from a large-scale, cross-sectional study

The present study explored the associations between school start time and sleep habits among older adolescents, and whether these associations depended on circadian preference. The sample comprised 4010 high school students aged 16-17 years who completed a web-based survey on habitual school start time, sleep, and health. The survey included the Munich ChronoType Questionnaire, and the short version of the Horne-Östberg Morningness-Eveningness Questionnaire. Students were categorised according to habitual school start time (before 08:00 hours, 08:00 hours, 08:15 hours, 08:30 hours or after 08:30 hours) and circadian preference (morning, intermediate or evening). Data were analysed using two-way analyses of variance (school start time × circadian preference) and linear regression analyses. Results showed an overall effect of school start time on school day sleep duration (main effect, p < 0.001), with the latest school starters having the longest, and the earliest school starters having the shortest sleep duration (7:03 hr versus 6:16 hr; Tukey HSD p < 0.001). Similarly, later school starters generally reported shorter social jetlag and later school day wake-up times than earlier starting students (both main effect p < 0.001). Circadian preference did not modify these associations (interaction effects p > 0.05). In the crude regression analysis, 15 min later school start was associated with 7.2 min more sleep (p < 0.001). School start time remained a significant predictor of school day sleep duration when adjusted for sex, parental educational level and circadian preference (p < 0.001). Results suggest that school start time is a significant predictor of school day sleep duration among adolescents.

[Sleepiness among adolescents: etiology and multiple consequences]

Over the past century a dramatic decline in sleep duration among adolescents, such as more than one hour of sleep loss per night, has been reported. A debt in sleep duration could lead to sleep deprivation, a major risk factor associated with daytime sleepiness. Sleepiness refers to the inability to maintain an adequate level of alertness during the day which may result in more or less being able to control falling asleep at inappropriate times. This literature review updates on sleepiness regarding its characteristics, etiology and consequences on adolescents. Studies revealed that from 25 % to 78 % of adolescents had reported sleepiness. Its manifestations may include heavy lids, yawns, difficulties to concentrate and emotional irritability. In addition, while it is recommended that adolescents under 18 years-old should sleep from eight to ten hours a night, only 63 % of them actually do so. The etiology of sleep deprivation and sleepiness in this population can be explained by various biological and societal factors. First, the sleep-wake cycle of adolescents shows a biological shift from the beginning of pubertal maturation, described as a perfect storm. It refers to a social jetlag by going to sleep and waking up later and accumulating a sleep debt during weekdays which they try to reimburse during weekends. This phenomenon can be explained by physiological changes such as a slower accumulation of sleep pressure. In addition to this perfect storm, environmental and societal factors contribute to the social jetlag and reduce sleep duration in adolescents. Screen exposure before bedtime can delay sleep and wake onset, which is a risk factor for sleeping debt. Substance use such as caffeine, cigarettes or electronic vaporizer, ADHD or freely available medication, alcohol, cannabis use or drug consumption could further disrupt sleep-wake cycle by stimulating, depressing or otherwise disrupting the central nervous system. Early, before 8:30 am, class start times have been associated with chronic sleep deprivation, higher level of sleepiness and delayed melatonin peak secretion. Adolescents working or doing extracurricular occupations for more than 20hours a week are more at risk for reduced sleep duration and sleepiness. Parental supervision about sleep during the weekdays were associated with more appropriate bedtime. Adolescents from low socio-demographic characteristics and from minority ethnic groups have reported displaying a shorter sleep duration. Finally, sleep disorders of a physiological origin such as narcolepsy, sleep apnea or restless legs syndrome, may explain the sleep deprivation and sleepiness. Sleep deprivation and sleepiness in adolescents have consequences on their health. Cognitive functioning, such as problem solving, attention or memory, as well as school performance, can be compromised by sleep deprivation and sleepiness. At the psychological level, adolescents reporting sleepiness are more prone to display mental health problems: associations were found between sleepiness and subjective perception of depression, anxiety, somatic complaints as well as with antisocial behaviors. Finally, 68 % of 16 year-old adolescents reported they drove a car, and the reported sleepiness could lead to road accidents due to reduced attentional functioning, reaction time and decision-making abilities. In the United-States, from 7 % to 16.5 % of deadly accidents were related to driving while drowsy. Highlighting etiology and problems associated with sleep deprivation and sleepiness in adolescents could guide researchers and clinicians towards the development of possible interventions. Public health measures and knowledge transfer programs regarding modifiable psychosocial and societal factors associated with sleep-wake bioregulation could increase awareness in parents as well as in political and societal decision makers.

The Influence of Light and Physical Activity on the Timing and Duration of Sleep: Insights from a Natural Model of Dance Training in Shifts

Environmental, social, and behavioral variables influence sleep timing and duration. Using wrist-worn accelerometers, we recorded 31 dancers (age = 22.6 ± 3.5) for 17 days and who trained either in the morning (n = 15) or in the late evening (n = 16). We estimated the dancers' daily sleep pattern: onset, end, and duration. In addition, their minutes of moderate-to-vigorous physical activity (MVPA) and mean light illuminance were also calculated daily and for the morning-shift and late-evening-shift time windows. On training days, the shifts involved differences in sleep timing, alarm-driven waking frequency, and the pattern of light exposure and MVPA duration. Sleep was strongly advanced when dancers trained in the morning and when alarms were used, while morning light had a low influence. Sleep was delayed when dancers were more exposed to light and displayed longer MVPA during the late evening. Sleep duration was strongly reduced on weekends and when alarms were used. A small reduction in sleep duration was also observed when morning illuminance was lower or when late evening MVPA was longer. Training in shifts influenced the timing of environmental and behavioral factors, which added up to shape dancers' sleep timing and duration.

Understanding the Need for Sleep to Improve Cognition

The restorative function of sleep is shaped by its duration, timing, continuity, subjective quality, and efficiency. Current sleep recommendations specify only nocturnal duration and have been largely derived from sleep self-reports that can be imprecise and miss relevant details. Sleep duration, preferred timing, and ability to withstand sleep deprivation are heritable traits whose expression may change with age and affect the optimal sleep prescription for an individual. Prevailing societal norms and circumstances related to work and relationships interact to influence sleep opportunity and quality. The value of allocating time for sleep is revealed by the impact of its restriction on behavior, functional brain imaging, sleep macrostructure, and late-life cognition. Augmentation of sleep slow oscillations and spindles have been proposed for enhancing sleep quality, but they inconsistently achieve their goal. Crafting bespoke sleep recommendations could benefit from large-scale, longitudinal collection of objective sleep data integrated with behavioral and self-reported data.

Analysis of Daily Sleep Diary Measures From Multilayer Extended-Release Methylphenidate (PRC-063) Studies in Children and Adults With ADHD

OBJECTIVE

To compare the effect of a once-daily extended-release methylphenidate formulation (PRC-063) versus placebo on sleep, measured via daily electronic diary in two clinical trials in pediatric (6-12 years) and adult (≥18 years) patients with attention deficit hyperactivity disorder (ADHD).

METHOD

A diary was completed by adult patients or parents/caregivers of pediatric patients during two randomized, double-blind, placebo-controlled laboratory classroom studies. Following dose optimization of PRC-063, patients were randomized to 1 week of double-blind treatment with PRC-063 or placebo before attending a full-day laboratory classroom session.

RESULTS

In the studies, 148 pediatric patients and 239 adult patients were randomized to either PRC-063 or placebo. When compared with the diaries of placebo patients, the sleep diaries in both pediatric and adult patients showed no statistical difference in total sleep time, efficiency, or latency.

CONCLUSION

PRC-063 did not impact subjective measures of sleep versus placebo in pediatric and adult patients with ADHD.

Association between parental control and depressive symptoms among college freshmen in China: The chain mediating role of chronotype and sleep quality

BACKGROUND

College freshmen tend to have more psychological and behavioral problems compared with other populations, especially depressive symptoms. Perceived parental control has been proved to play a significant role in mental health among children and adolescents. Based on the theoretical and empirical research of chronotype and sleep quality, this study constructed a chain mediating model to examine whether they mediated the relationship between parental control and depressive symptoms among Chinese college freshmen.

METHODS

A total of 2014 college freshmen from Dali University were recruited to participate in this study and completed self-report Parental Bonding Instrument (PBI), Morningness-Eveningness Questionnaire (MEQ), Pittsburgh Sleep Quality Index (PSQI) and Self-Rating Depression Scale (SDS). PROCESS 3.5 for SPSS was applied to determine the chain mediating effect of chronotype and sleep quality between parental control and depressive symptoms.

RESULTS

College freshmen with depressive symptoms have higher levels of parental control and worse subjective sleep quality than normal population (all p < 0.001). All study variables are correlated with each other, while chronotype has no significant association with depressive symptoms (r = -0.03, p > 0.05). Both maternal and paternal control have a direct link with depressive symptoms (β = 0.86, p < 0.001; β = 0.88, p < 0.001). Parental control could affect depressive symptoms via the independent mediating effect of sleep quality and the chain mediating effect of chronotype and sleep quality. The total indirect effects of maternal and paternal control on depressive symptoms are 0.93 and 0.94, respectively.

CONCLUSIONS

Chronotype and sleep quality could mediate the association between parental control and depressive symptoms.

Delayed high school start times and graduation and attendance rates over 4 years: the impact of race and socioeconomics

STUDY OBJECTIVES

The current study was designed to examine if improvements in high school graduation and attendance rates persist 4 years after start times later than 8:30 am. Socioeconomic status and race were accounted for in the graduation analysis.

METHODS

School-wide attendance and graduation records (n = 28 schools) from 1999-2017 were analyzed in August of 2021 using a repeated-measures analysis of variance at 5 points in time, 1 year predelay and 4 consecutive years postdelay start times.

RESULTS

Graduation rates for students in grade 12 (n > 47,000) after postdelay year 4 increased from 80% to 90% (P < .001) and attendance rates in grades 9-12 (n > 80,000) improved from 90% to 93% (P = .012).

CONCLUSIONS

Attendance and graduation rates for all students improved after 4 years following a delayed start. Economically disadvantaged students and Black students showed significant changes in graduation rates postdelay year 4 and White students significantly improved postdelay years 2, 3, and 4. Adolescent students, especially economically and racially disadvantaged students, have a vulnerability for obtaining adequate sleep. Delaying high school start times is a cost-effective intervention that could promote sufficient sleep and boost graduation and attendance rates.

CITATION

McKeever PM, Dodd R, O'Sullivan DM. Delayed high school start times and graduation and attendance rates over 4 years: the impact of race and socioeconomics. J Clin Sleep Med. 2022;18(11):2537-2543.

Nonpharmacological Interventions to Lengthen Sleep Duration in Healthy Children: A Systematic Review and Meta-analysis

Importance

Adequate sleep duration is necessary for many aspects of child health, development, and well-being, yet sleep durations for children are declining, and effective strategies to increase sleep in healthy children remain to be elucidated.

Objective

To determine whether nonpharmaceutical interventions to improve sleep duration in healthy children are effective and to identify the key components of these interventions.

Data Sources

CENTRAL, MEDLINE, Embase, PsycINFO, Web of Science Core collection, ClinicalTrials.gov, and WHO trials databases were searched from inception to November 15, 2021.

Study Selection

Randomized clinical trials of interventions to improve sleep duration in healthy children were independently screened by 2 researchers. A total of 28 478 studies were identified.

Data Extraction and Synthesis

Data were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) reporting guideline. Random-effects meta-analytic models were used to estimate pooled effect sizes.

Main Outcomes and Measures

Difference in sleep duration, measured in minutes.

Results

A total of 13 539 child participants from 45 randomized clinical trials were included. Of these, 6897 (50.9%) were in the intervention group and 6642 (49.1%) in the control group, and the mean age ranged from 18 months to 19 years. Pooled results indicate that sleep interventions were associated with 10.5 minutes (95% CI, 5.6-15.4) longer nocturnal sleep duration. There was substantial variation between trials. Sources of variation that were not associated with the study effect size included age group, whether the population was identified as having a sleep problem or being at a socioeconomic disadvantage (eg, coming from a low-income family or area), method of assessment of sleep duration (objective vs subjective), location of intervention delivery (home vs school), whether interventions were delivered in person or used parental involvement, whether behavioral theory was used, environmental change, or had greater or lower intensity. Interventions that included earlier bedtimes were associated with a 47-minute sleep extension (95% CI, 18.9-75.0; 3 trials) compared with remaining studies (7.4 minutes; 95% CI, 2.9-11.8; 42 trials) (P = .006 for group difference). Trials of shorter duration (6 months or less) had larger effects.

Conclusions and Relevance

Interventions focused on earlier bedtimes may offer a simple, pragmatic, effective way to meaningfully increase sleep duration that could have important benefits for child health.

Psychosocial factors related to sleep in adolescents and their willingness to participate in the development of a healthy sleep intervention: a focus group study

BACKGROUND

Over the last decades, adolescents' sleep has deteriorated, suggesting the need for effective healthy sleep interventions. To develop such interventions, it is important to first gather insight into the possible factors related to sleep. Moreover, previous research has indicated that chances of intervention effectivity could be increased by actively involving adolescents when developing such interventions. This study examined psychosocial factors related to sleep in adolescents and investigated adolescents' willingness to participate in the development of a healthy sleep intervention.

METHODS

Nine focus group interviews were conducted with seventy-two adolescents (63.9% girls, 14.8 (± 1.0) years) using a standardized interview guide. Interviews were audio-recorded and thematic content analysis was performed using Nvivo 11.

RESULTS

Adolescents showed limited knowledge concerning sleep guidelines, sleep hygiene and the long-term consequences of sleep deficiency, but they demonstrated adequate knowledge of the short-term consequences. Positive attitudes towards sleep were outweighed by positive attitudes towards other behaviors such as screen time. In addition, adolescents reported leisure activities, the use of smartphones and television, high amounts of schoolwork, early school start time and excessive worrying as barriers for healthy sleep. Perceived behavioral control towards changing sleep was reported to be low and norms about sufficient sleep among peers were perceived as negative. Although some adolescents indicated that parental rules provoke feelings of frustration, others indicated these have a positive influence on their sleep. Finally, adolescents emphasized that it would be important to allow students to participate in the development process of healthy sleep interventions at school, although adult supervision would be necessary.

CONCLUSION

Future interventions promoting healthy sleep in adolescents could focus on enhancing knowledge of sleep guidelines, sleep hygiene and the consequences of sleep deficiency, and on enhancing perceived behavioral control towards changing sleep. Interventions could also focus on prioritizing positive sleep attitudes over positive attitudes towards screen time, finding solutions for barriers towards healthy sleep and creating a positive perceived norm regarding healthy sleep. Involving adolescents in intervention development could lead to intervention components that match their specific needs and are more attractive for them.

Multiple positive outcomes of a later school starting time for adolescents

OBJECTIVE

We tested the effect of later school start time (LSST) by 1 hour during 1 week on sleep, sleepiness, and mood profile using within-subject design.

DESIGN

A within-subject 3-weeks-long interventional study. A baseline week with school starting at 7:30 AM (week A), followed by an intervention week with school starting at 8:30 AM (week B), and a recovery week with school start time back to 7:30 AM (week C). Mixed model for repeated measures analysis was applied to test for the LSST effect between weeks.

SETTING

A private high school with high level of socioeconomic status.

PARTICIPANTS

Forty-eight adolescents from 3 different high school years.

MEASUREMENTS

Participants were invited to wear actigraphs continuously during the 3 experimental weeks. Somnolence was obtained every school day twice, at arrival and before departure of school. Sleep quality and mood profile were evaluated by standard measures by the end of each school week, resulting in 3 repeated measures for each variable.

RESULTS

Thirty-eight adolescents completed the study. Adolescents woke up later during week B (7:42 ± 00:30) in comparison to weeks A (6:54 ± 00:12) and C (6:46 ± 00:15) (p < .001), with no significant change on sleep onset between weeks (p = .657), resulting in a longer sleep duration in week B (p < .001). Significant improvements on sleepiness and mood profile were also reported during week B.

CONCLUSIONS

Starting school later was effective in improving multiple aspects from sleep patterns, subjective sleepiness, and mood profile.

Sleep's role in the development and resolution of adolescent depression

Two adolescent mental health fields - sleep and depression - have advanced largely in parallel until about four years ago. Although sleep problems have been thought to be a symptom of adolescent depression, emerging evidence suggests that sleep difficulties arise before depression does. In this Review, we describe how the combination of adolescent sleep biology and psychology uniquely predispose adolescents to develop depression. We describe multiple pathways and contributors, including a delayed circadian rhythm, restricted sleep duration and greater opportunity for repetitive negative thinking while waiting for sleep. We match each contributor with evidence-based sleep interventions, including bright light therapy, exogenous melatonin and cognitive-behaviour therapy techniques. Such treatments improve sleep and alleviate depression symptoms, highlighting the utility of sleep treatment for comorbid disorders experienced by adolescents.

Association between quality of sleep and screen time during the COVID-19 outbreak among adolescents in the United Arab Emirates

The COVID-19 pandemic had a major impact on people of all ages. Adolescents' exposure to online learning is linked to excessive screen time on digital devices, which leads to poor sleep quality. This study aimed to investigate the association between screen time on different electronic devices and sleep quality among adolescents in the United Arab Emirates. This study was based on a self-reported questionnaire, which was administered online to school-aged adolescents (aged 12-19 years). The multicomponent questionnaire collected information on sociodemographic characteristics, sleep quality using the Pittsburgh Sleep Quality Index (PSQI), and screen time (minutes) on TV, TV-connected devices, laptops, smartphones, and tablets on weekdays, weeknight, and weekends using the Screen Time Questionnaire (STQ). Univariate and multivariate analyses were used to identify factors correlated with poor sleep quality. A total of 1720 adolescents were recruited from private and public schools (mean age 14.6 ± 1.97 years). The mean PSQI score was 8.09 ± 3.37, and 74.3% of participants reported poor sleep (cutoff score >5). Mean scores were highest for the sleep latency (1.85 ± 0.97) and sleep disturbance (1.56 ± 0.62) domains. The highest STQ score was observed for smartphones, with a median screen time of 420 min on weekdays and 300 min on weekends. Screen time related to smartphones on weekends (p = 0.003) and increased screen time in bed (p < 0.001) were significantly associated with poor sleep. Our results confirmed the correlation between sleep and screen time in adolescents. The results may inform educational polices that target screen time and sleep among adolescents during and after the COVID-19 pandemic.

Boosting Student Wellbeing Despite a Pandemic: Positive Psychology Interventions and the Impact of Sleep in the United Arab Emirates

Positive psychology interventions hold great promise as schools around the world look to increase the wellbeing of young people. To reach this aim, a program was developed to generate positive emotions, as well as improve life satisfaction, mental toughness and perceptions of school kindness in 538 expatriate students in Dubai, United Arab Emirates. Starting in September 2019, the program included a range of positive psychology interventions such as gratitude, acts of kindness and mental contrasting as examples. Life satisfaction and mental toughness at mid-year were sustained or grew by the end of the year. Positive affect, emotional wellbeing and social wellbeing increased at post-intervention 1, compared to baseline. However, this improvement reverted to baseline levels at post-intervention 2, when data were collected during the COVID-19 pandemic. Only psychological wellbeing, negative affect, perceptions of control, and school kindness were increased at post-intervention 2. During the lockdown, students moved less, but slept and scrolled more. Those who extended their sleep duration reported greater wellbeing. Boosting wellbeing through the use of positive psychology interventions works – even in a pandemic – and extended sleep duration appears to be a driving factor for this observation.

Sleep and Health-Related Characteristics among Adolescents during COVID-19: An Update

Two opposing effects on adolescents' health during COVID-19 lockdown have been described: A beneficial one due to longer sleep times during school closures and a detrimental one of psychological distress. This study investigated how sleep and health changed in the course of the pandemic when schools were open again. Overall, 12,238 adolescents in Switzerland participated in three cross-sectional online surveys: In 2017 under regular conditions (control group), during pandemic school closures in 2020 (closure group), and in 2021 still under pandemic conditions, but schools were open again (postclosure group). Sleep behavior and health-related characteristics (health-related quality of life; caffeine, alcohol, and nicotine use) in all three groups and depressive symptoms in the closure and postclosure groups were assessed. The sleep period on school days was longer in the closure group (median 9.00 h, interquartile range 8.25-9.75) and similar in the postclosure (7.92, 7.00-8.50) compared to the control group (7.75, 7.08-8.33). Health-related characteristics were better during school closures and similar to worse in the postclosure compared to the control group. Depressive symptom levels were higher in the postclosure than in the closure group. Therefore, beneficial effects were specific to school closures and adolescents' psychological distress increased over the course of the pandemic.

A primer on sleep for MFTs: Implications and practical considerations

Despite many marriage and family therapists (MFTs) utilizing the Biopsychosocial-Spiritual (BPSS) framework in assessment and treatment, there is still a lack of education on sleep and the implications for mental, emotional, and relational health. Newer research within many fields highlights the far-reaching spillover effects of short or poor-quality sleep that can affect our clients. MFTs need to know how to assess, how to provide proper psychoeducation, how to apply this knowledge in clinical settings, and how to collaborate with other healthcare providers. As such, the purpose of this article is threefold: (a) review the biopsychosocial-spiritual importance of sleep; (b) equip MFTs with information on sleep assessment, how to identify situations for referral, and how to provide psychoeducation on sleep hygiene; and (c) review important considerations for research and practice for MFTs.

Equal Benefits? An Examination of the Potential Consequences of Later School Start Times for Adolescents and Their Mental Health

BACKGROUND

Given the documented benefits of later school start times on adolescents' mental health, the aim of the current study was to examine if the association between school start times and depressive symptoms differed across adolescents from families of different socioeconomic status levels.

METHODS

Using a cross-sectional design, the current study incorporated an online survey for high school students and their parents across the United States, with average sleep duration measured through a 7-day sleep diary. A total of 193 adolescent (Mean_age  = 15.7 years old, SD = .94; 54.4% female; 71% white) and parent (Mean_age  = 47.6 years old, SD = 5.4; 80% female; 79% white) dyads participated. Adolescents reported on depressive symptoms, sleep quality and duration, chronotype, and demographic covariates; parents reported on school start times and socioeconomic status.

RESULTS

Results suggested that only in adolescents from higher socioeconomic status families (+1 SD) did the association between later start times and fewer depressive symptoms emerge as significant.

CONCLUSIONS

Although more school start times research is needed to understand its impact across diverse groups of students, current findings suggest a disproportionate benefit of reduced depression for youth from families of higher socioeconomic status with having a later start time.

A 4-year longitudinal study investigating the relationship between flexible school starts and grades

The mismatch between teenagers' late sleep phase and early school start times results in acute and chronic sleep reductions. This is not only harmful for learning but may reduce career prospects and widen social inequalities. Delaying school start times has been shown to improve sleep at least short-term but whether this translates to better achievement is unresolved. Here, we studied whether 0.5-1.5 years of exposure to a flexible school start system, with the daily choice of an 8 AM or 8:50 AM-start, allowed secondary school students (n = 63-157, 14-21 years) to improve their quarterly school grades in a 4-year longitudinal pre-post design. We investigated whether sleep, changes in sleep or frequency of later starts predicted grade improvements. Mixed model regressions with 5111-16,724 official grades as outcomes did not indicate grade improvements in the flexible system per se or with observed sleep variables nor their changes-the covariates academic quarter, discipline and grade level had a greater effect in our sample. Importantly, our finding that intermittent sleep benefits did not translate into detectable grade changes does not preclude improvements in learning and cognition in our sample. However, it highlights that grades are likely suboptimal to evaluate timetabling interventions despite their importance for future success.

Sleep improvements on days with later school starts persist after 1 year in a flexible start system

Early school times fundamentally clash with the late sleep of teenagers. This mismatch results in chronic sleep deprivation posing acute and long-term health risks and impairing students' learning. Despite immediate short-term benefits for sleep, the long-term effects of later starts remain unresolved. In a pre-post design over 1 year, we studied a unique flexible school start system, in which 10–12th grade students chose daily between an 8:00 or 8:50AM-start. Missed study time (8:00–8:50) was compensated for during gap periods or after classes. Based on 2 waves (6–9 weeks of sleep diary each), we found that students maintained their ~ 1-h-sleep gain on later days, longitudinally (n = 28) and cross-sectionally (n = 79). This gain was independent of chronotype and frequency of later starts but attenuated for boys after 1 year. Students showed persistently better sleep quality and reduced alarm-driven waking and reported psychological benefits (n = 93) like improved motivation, concentration, and study quality on later days. Nonetheless, students chose later starts only infrequently (median 2 days/week), precluding detectable sleep extensions in the flexible system overall. Reasons for not choosing late starts were the need to make up lost study time, preference for extra study time and transport issues. Whether flexible systems constitute an appealing alternative to fixed delays given possible circadian and psychological advantages warrants further investigation.

Association Between Homeschooling and Adolescent Sleep Duration and Health During COVID-19 Pandemic High School Closures

IMPORTANCE

Although negative associations of COVID-19 pandemic high school closures with adolescents' health have been demonstrated repeatedly, some research has reported a beneficial association of these closures with adolescents' sleep. The present study was, to our knowledge, the first to combine both perspectives.

OBJECTIVE

To investigate associations between adolescents' sleep and health-related characteristics during COVID-19 pandemic school closures in Switzerland.

DESIGN, SETTING, AND PARTICIPANTS

This survey study used cross-sectional online surveys circulated among the students of 21 public high schools in Zurich, Switzerland. The control sample completed the survey under regular, prepandemic conditions (May to July 2017) and the lockdown sample during school closures (May to June 2020). Survey respondents were included in the study if they provided their sex, age, and school.

EXPOSURES

High school closures during the first COVID-19 pandemic wave in Switzerland (March 13 to June 6, 2020).

MAIN OUTCOMES AND MEASURES

Sleep-wake patterns, health-related quality of life (HRQoL, assessed by the KIDSCREEN-10 questionnaire), substance use (caffeine, alcohol, and nicotine), and depressive symptoms (lockdown sample only; assessed using the withdrawn/depressed scale from the Youth Self Report). Multilevel regression models were used to assess sample differences and associations of health-related characteristics with sleep duration and depressive symptoms.

RESULTS

The total sample consisted of 8972 students, including 5308 (59.2%) in the control sample (3454 [65.1%] female) and 3664 (40.8%) in the lockdown sample (2429 [66.3%] female); the median age in both samples was 16 years (IQR, 15-17 years). During school closures, the sleep period on scheduled days was 75 minutes longer (semipartial R2 statistic [R2β*], 0.238; 95% CI, 0.222-0.254; P < .001) and the students had better HRQoL (R2β*, 0.007; 95% CI, 0.004-0.012; P < .001) and less consumption of caffeine (R2β*, 0.010; 95% CI, 0.006-0.015; P < .001) and alcohol (R2β*, 0.014; 95% CI, 0.008-0.022; P < .001). Longer sleep duration was associated with better HRQoL (R2β*, 0.027; 95% CI, 0.020-0.034; P < .001) and less caffeine consumption (R2β*, 0.013; 95% CI, 0.009-0.019; P < .001). In the lockdown sample, an inverse association was found between depressive symptoms and HRQoL (R2β*, 0.285; 95% CI, 0.260-.0311; P < .001) and a positive association was found with caffeine consumption (R2β*, 0.003; 95% CI, 0.000-0.008; P = .01).

CONCLUSIONS AND RELEVANCE

In this survey study, 2 opposing associations between school closures and adolescents' health were identified: a negative association with psychological distress and a beneficial association with increased sleep duration. These findings should be considered when evaluating and implementing school closures. Furthermore, the findings provide support for delaying school start times for adolescents.

Adolescent sleep health and school start times: Setting the research agenda for California and beyond: A research summit summary: A research summit summary

In fall 2019, California passed and signed into law SB328, the first US statewide legislation explicitly designed to protect adolescent sleep health by requiring most California public school districts to start no earlier than 8:00 AM for middle schools and 8:30 AM for high schools. Recognizing the unique opportunity presented by the bill's 3-year implementation period, a group of experts in adolescent sleep and school start times held a virtual summit on January 22-23, 2021 to (1) summarize the research on adolescent sleep and school start time change; (2) develop recommendations for relevant, refined, and innovative research areas and research questions; (3) provide input regarding research design, methodology, and implementation; and (4) offer a forum for networking, exchanging ideas, and establishing interdisciplinary research collaborations. Participants represented a multidisciplinary range of academic backgrounds including sleep and circadian biology, neuroscience, education, medicine, public health, mental health, safety, public policy, economics, implementation science, criminology, diversity studies, and science communication. This paper summarizes summit presentations regarding current knowledge on adolescent sleep health and school start times and key research recommendations from small group workshops on topics including research design and tools, methodological issues, sleep health disparities, logistical challenges in conducting school-based research, public-health impact, and novel and expanded approaches to research.

Teachers' preference for later school start times

Early morning school start times conflict with biologically determined sleep phase preference and thus contribute to common sleep deficits. This conflict is most pronounced in adolescents, and numerous studies have confirmed that later school start times are beneficial for their sleep and health. However, the conflict continues to exist beyond adolescence and, accordingly, also teachers might benefit from later school start times, but this has gained little attention so far. Importantly, teachers’ resistance to delay school start time is one of the key barriers for a successful implementation and, therefore, teachers’ school start time preferences and influencing factors are important to consider. To this end, we conducted an online survey. Teachers (n = 694, 56.1% female) from 17 high schools in Zurich, Switzerland, participated in the study. They indicated their school start time preference. In addition, four predictor blocks were assessed: sociodemographic, school‐/work‐related, and sleep characteristics, as well as teachers’ perception of students in the first morning lesson. Mixed models were applied to predict the preference. The majority (51%) endorsed later school start times (median preferred delay 25.2 min). School start time, sleep characteristics and perception of students in the first morning lesson were significant predictors for the preference. Thus, teachers with more misaligned sleep and higher awareness for students’ issues in the early morning were more likely to report a preference. This suggests psychoeducation about sleep biology throughout life span to be an effective measure to increase teachers’ support to delay school start time, especially because also they themselves are likely to benefit from later school start times.

School start times and academic achievement - A systematic review on grades and test scores

Early school times clash with the late sleep of adolescents, leading to wide-spread sleep restriction in students. Evidence suggests that delaying school starts is beneficial for sleep and recent studies investigated whether this also translates into improved academic achievement. We thus conducted a systematic review of the literature on school start times, grades and test scores in middle and high-school students. We reviewed 21 studies following the PRISMA guidelines and assessed the evidence quality using a pre-defined risk of bias tool. Nine studies reported no association of later starts with achievement, while the remaining reported mixed (5), positive (5), negative (1) or unclear (1) results. Considering the heterogeneity in academic outcomes, study types, amount of delay and exposure, and the substantial risk of bias, a meta-analysis was not warranted - instead we provide grouped reviews and discussion. Overall, no generalisable improvements in achievement with later starts emerge beyond the level of single studies. This does not necessarily preclude improvements in students' learning but highlights shortcomings of the literature and the challenges of using grades and test scores to operationalise academic achievement. Given other previously reported positive outcomes, our results suggest that schools could start later while achievement is likely maintained.

Association of Delaying School Start Time With Sleep-Wake Behaviors Among Adolescents

PURPOSE

Few adolescents spend enough time asleep on school nights. This problem could be addressed by delaying high school start times, but does this translate to reduced prevalence of sleep-wake problems like awakening too early or feeling sleepy during the day?

METHODS

The START study (n = 2,414) followed a cohort of students from five Minnesota high schools to evaluate impacts of school start time delays. Participants were enrolled in ninth grade (Baseline) when all schools started early (7:30 or 7:45 a.m.). At Follow-Up 1 (10th grade) and Follow-Up 2 (11th grade), two schools had delayed their start times by 50 and 65 minutes while three comparison schools started at 7:30 a.m. Six sleep-wake behaviors were assessed at all three time points via survey. Generalized estimating equation models were used to investigate changes in sleep-wake problems between policy change and comparison schools.

RESULTS

The prevalence of sleep-wake problems at Baseline ranged from 11% for being late to class due to oversleeping to 48% for needing to be told to wake multiple times in the morning. Compared to students from comparison schools, students at policy change schools reported smaller increases in the prevalence of feeling sleepy daily and oversleeping and being late to class between 9th and 11th grade. After implementation of the delayed start, awakening too early was more common among students at policy change schools compared to the comparison schools.

CONCLUSIONS

This longitudinal study provides evidence that delaying high school start times reduces daytime sleepiness and school tardiness.