Drowsy Driving, Sleep Duration, and Chronotype in Adolescents

Sleep Deficiency in Adolescents: The School Start Time Debate

Adolescence is commonly accepted as a challenging time for sleep, with multiple factors contributing to sleep deficiency in adolescents. These include physiologic changes with shifts in their circadian rhythm; medical sleep disorders; and social, cultural, and environmental factors. Early school start times negatively affect sleep in adolescents as well, with poorer outcomes in their overall health, wellbeing, and performance. This article highlights the different contributing factors for sleep deficiency in adolescents and the consequences of sleep deficiency. In addition, the authors discuss the impact of delayed school start times in improving adolescents' sleep and overall function.

Extending weeknight sleep duration in late-sleeping adolescents using morning bright light on weekends: a 3-week maintenance study

Study Objectives

Our sleep extension intervention in adolescents showed that gradually shifting weekday bedtime earlier plus one weekend of morning bright light advanced circadian phase and increased weeknight sleep duration. Here, we examine at-home maintenance of these changes.

Methods

Fourteen adolescents (15.3-17.9 years; 7 female) completed a 7-week study. After usual sleep at home (2-week baseline), intervention participants (n = 8) gradually advanced weekday bedtime (1 hour earlier than baseline during week 3; 2 hours earlier in week 4) and received bright light (~6000 lux; 2.5 hours) on both mornings of the intervening weekend. During three maintenance weeks, intervention participants were instructed to maintain their school-day wake-up time on all days, keep their early week four bedtimes, except on weekends when they could go to bed up to 1 hour later, and get a 2.5-hour light box exposure within 5 minutes of waking on one morning (Saturday or Sunday) of both weekends at home. Control participants (n = 6) slept as usual at home and did not receive weekend bright light. Dim light melatonin onset (DLMO) was measured after the 2-week baseline, 2-week intervention, and 3-week maintenance in all participants. Actigraphic sleep-wake was collected throughout.

Results

After the 2-week intervention, DLMOs advanced more compared to control (37.0 ± 40.0 minutes vs. -14.7 ± 16.6 minutes), weekday sleep duration increased by 69.7 ± 27.8 minutes and sleep onset was 103.7 ± 14.2 minutes earlier compared to baseline. After three maintenance weeks, intervention participants showed negligible DLMO delays (-4.9 ± 22.9 minutes); weekday fall-asleep times and sleep durations also remained stable.

Conclusions

Early circadian phase and extended sleep can be maintained with at-home weekend bright light.

[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.

Extending weeknight sleep of delayed adolescents using weekend morning bright light and evening time management

STUDY OBJECTIVES

Shift sleep onset earlier and extend school-night sleep duration of adolescents.

METHODS

Forty-six adolescents (14.5-17.9 years; 24 females) with habitual short sleep (≤7 h) and late bedtimes (≥23:00) on school nights slept as usual for 2 weeks (baseline). Then, there were three weekends and two sets of five weekdays in between. Circadian phase (Dim Light Melatonin Onset, DLMO) was measured in the laboratory on the first and third weekend. On weekdays, the "Intervention" group gradually advanced school-night bedtime (1 h earlier than baseline during week 1; 2 h earlier than baseline during week 2). Individualized evening time management plans ("Sleep RouTeen") were developed to facilitate earlier bedtimes. On the second weekend, Intervention participants received bright light (~6000 lux; 2.5 h) on both mornings. A control group completed the first and third weekend but not the second. They slept as usual and had no evening time management plan. Weekday sleep onset time and duration were derived from actigraphy.

RESULTS

Dim light melatonin onset (DLMO) advanced more in the Intervention (0.6 ± 0.8 h) compared to the Control (-0.1 ± 0.8 h) group. By week 2, the Intervention group fell asleep 1.5 ± 0.7 h earlier and sleep duration increased by 1.2 ± 0.7 h; sleep did not systematically change in the Control group.

CONCLUSIONS

This multi-pronged circadian-based intervention effectively increased school-night sleep duration for adolescents reporting chronic sleep restriction. Adolescents with early circadian phases may only need a time management plan, whereas those with later phases probably need both time management and morning bright light.

CLINICAL TRIALS

Teen School-Night Sleep Extension: An Intervention Targeting the Circadian System (#NCT04087603): https://clinicaltrials.gov/ct2/show/NCT04087603.

Fatigue in transportation operations: A contextual factors survey among Iranian suburban drivers

BACKGROUND

Fatigue, as a persistent and serious occupational hazard, plays an important role in traffic accidents by reducing the driver's ability to maneuver with the vehicle and increasing the likelihood of falling asleep at the wheel.

OBJECTIVE

The purpose of this study was to identify the individual contextual factors, sleep condition, lifestyle, job characteristics, environmental, and economic conditions that affect the fatigue and alertness of Iranian suburban bus drivers.

METHODS

A questionnaire-based cross-sectional survey was used for this study. Non-probability sampling was used to study 401 suburban bus drivers from Tehran province, Iran, ranging in age from 24 to 67 years. The SPSS22 statistical software V27 was used for the analysis.

RESULTS

Approximately half of the participants (50.5%) had experienced fatigue while driving in the previous six months. According to a logistic regression analysis, the contextual factors were all independently related to falling asleep and fatigue while driving.

CONCLUSION

This study provides a thorough understanding of the contextual factors related to drowsy driving and emphasizes the importance of taking these things into consideration when developing interventions aimed at improving the driver's wellbeing and health and lowering the risk of errors and accidents.

Sleep Deficiency in Adolescents: The School Start Time Debate

Adolescence is commonly accepted as a challenging time for sleep, with multiple factors contributing to sleep deficiency in adolescents. These include physiologic changes with shifts in their circadian rhythm; medical sleep disorders; and social, cultural, and environmental factors. Early school start times negatively affect sleep in adolescents as well, with poorer outcomes in their overall health, wellbeing, and performance. This article highlights the different contributing factors for sleep deficiency in adolescents and the consequences of sleep deficiency. In addition, the authors discuss the impact of delayed school start times in improving adolescents' sleep and overall function.

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.

Effect of a Multilayer, Extended-Release Methylphenidate Formulation (PRC-063) on Sleep in Adolescents with Attention-Deficit/Hyperactivity Disorder: A Randomized, Double-Blind, Fixed-Dose, Placebo-Controlled Trial Followed by a 6-Month Open-Label Follow-Up

Objectives: We analyzed patient-reported sleep parameters for an extended-release methylphenidate formulation (PRC-063) in adolescents with attention-deficit/hyperactivity disorder. Methods: Clinical efficacy and long-term safety/tolerability data from a 4-week, double-blind, placebo-controlled, fixed-dose study (NCT02139111) and a subsequent 6-month, optimized-dose, open-label extension (OLE) study (NCT02168127) were used. In the double-blind study, participants were randomly assigned 1:1:1:1:1 to one of four doses of PRC-063 (25, 45, 70, or 85 mg/day) or placebo. In both the double-blind and OLE studies, sleep outcomes were assessed using the Pittsburgh Sleep Quality Index (PSQI). Results: During double-blind treatment, no statistically significant least-squares mean difference in change from baseline between PRC-063 (all doses combined; N = 293) and placebo (N = 74) was found for either global PSQI score (-0.3 vs. -0.5; p = 0.6110) or scores for any of the seven PSQI subscales. Compared with the placebo group, a marginally higher proportion of patients in the PRC-063 group (all doses combined) went from being poor to good sleepers (global PSQI score ≤5; 14.4% vs. 11.3%). In a logistic regression analysis, study treatment was not a predictor of poor sleep (p = 0.5368) at the end of the double-blind study. In the OLE study, there was a trend of improvement in sleep after 1 month of individualized dosing that was maintained through 6 months. Sleep efficiency (time asleep as a proportion of time in bed) showed improvement at the end of the OLE study. Conclusion: While individual patients may experience changes in sleep as an adverse event, group data evaluating sleep as an outcome found there were no differences between PRC-063 and placebo in self-reported sleep outcomes on the PSQI.

School start time change and motor vehicle crashes in adolescent drivers

STUDY OBJECTIVES

The aim of this study was to examine the association between a 50-minute delay (7:20 am to 8:10 am) in high school start times in Fairfax County (FC) Virginia and changes in rates of adolescent motor vehicle crashes. Crash rates in FC were also compared to those in the rest of the state during the same time period.

METHODS

Virginia Department of Motor Vehicles crash data in drivers age 16 to 18 years old between September and June of each year in FC versus the rest of the state were compared in the combined 2-year periods preceding (2013-2014 and 2014-2015; T1) and following (2015-2016 and 2016-2017; T2) school start time change in the fall of 2015.

RESULTS

The crash rate per 1000 in 16- to 18-year-old licensed drivers in FC during T1 was significantly higher compared to T2, 31.63 versus 29.59 accidents per 1,000 (95% confidence interval, 1.0-1.14, odds ratio 1.07, P = .03). In contrast, adolescent crash rates in the rest of Virginia were not statistically significantly different at T1 versus T2. With regard to subtypes of crashes, there was a trend toward significance in distraction-related crashes per 1,000 in FC at T1 compared to T2 at 7.01 versus 6.13 (95% confidence interval, 0.99-1.31, odds ratio 1.14, P = .05), but were not significantly different in the remainder of the state.

CONCLUSIONS

The results of this study suggest that school start time delay is associated with decreased adolescent motor vehicle crash risk, with significant implications for public health and safety.

A quasi-experimental study of the impact of school start time changes on adolescents' mood, self-regulation, safety, and health

OBJECTIVE

To determine whether school start time changes impact adolescents' mood, self-regulation, safety, and health.

METHODS

In September 2015, two school start time changes were implemented in Fairfax County (VA) Public Schools: a 50-minute delay (to 8:10 am) for high schools and secondary schools and a 30-minute advance (to 7:30 am) for middle schools. We conducted cross-sectional surveys of students' sleep, mood, self-regulation, health, and safety before (2017 students) and after (1180 students) these changes.

RESULTS

Adjusted for confounders, a 50-minute delay was associated with a decreased prevalence of low mood (-4.7%; 95% confidence interval [CI]: -8.2%, -1.2%), drowsy driving, (-8.4%; 95% CI: -15.9%, -0.9%), and skipping breakfast (-4.2%; 95% CI: -8.1%, -0.2%) but no other significant changes. There were no significant changes associated with a 30-minute advance.

CONCLUSIONS

A 50-minute delay in school start time in high schools and secondary schools was associated with a decreased prevalence of low mood, drowsy driving, and skipping breakfast. A 30-minute advance in start time in middle schools was not associated with any appreciable changes.