Could later school start time improve adolescents’ sleep habits and general well-being?

Underestimating and neglecting the importance of sleep for adolescents can result in a huge negative impact on their health and well-being¹. Research indicates that some small policy changes could improve adolescents’ sleep habits and reduce daytime tiredness as well as improving mood.  Research has found that a later start to the school day can help improve adolescents’ well-being in several different ways ^{1, 2, 3,4}.

One US study² investigated the impact of delaying school start time by 30 minutes on students’ self-reported sleep, daytime tiredness, activity motivation and depressed mood. The study involved 278 students at a private boarding school who were surveyed before and after the introduction of the delayed school start time. After two months students reported sleeping longer, feeling less tired during the day, and scored lower for depression. Further, motivation for engaging in various activities increased.

In Switzerland in a sample of 2716 adolescents (mean age: 15.4 years) the relationship of sleep duration with  positive attitude towards life and academic achievement were examined ³.  The  study  indicated that students in a school that started 20 minutes later than the other schools, reported getting 16 min more sleep on school nights, which was  associated with less tiredness during the day. The authors recommend a short delay of school start times by 20 min which will have a substantial effect on adolescents’ sleep duration and daytime tiredness.

The most interesting experiment was conducted   in America on a sample of more than 9000 adolescents from a single, large, county-wide, school district: adolescents’ sleep habits and motor vehicle crash rates were assessed by questionnaire before and after a 1-hour delay in school start times⁴. It was found that a 1 hour delay in school start time resulted in increases in average hours of nightly sleep and decreases of catch-up sleep on weekends. Also average crash rates for teen drivers in the same county in the 2 years after the change in school start time dropped 16.5%, compared with the 2 years prior to the change, whereas teen crash rates for the rest of the state increased 7.8% over the same time period.

Unlike the USA, the UK has not systematically evaluated experiments to change the school start time, although three secondary schools in North Tyneside and Kent have tested a later start time of 10am and have reported  anecdotal information on reductions in absence and persistent absenteeism¹.

In the UK most secondary schools start at 8.30am, though there are number of schools starting at 9.00am. Based on current research, we might recommend policy makers to make further changes in school start times at least for half an hour, if not an hour. Meanwhile it would be interesting to compare the sleep habits and well-being of adolescents from those schools starting at 9am to those ones who start school earlier.

                                                                                                                        Ellen Klemera

1. www.ayph.org.uk
2. Owens, J. A., Belon, K., & Moss, P. (2010). Impact of delaying school start time on adolescent sleep, mood, and behaviour. Archives of Pediatrics & Adolescent Medicine, 164, 608–614.
3. Perkinson-Gloor ,N., Lemola,L., Grob,A.(2013) Sleep duration, positive attitude toward life, and academic achievement: The role of daytime tiredness, behavioural persistence, and school start times, Journal of Adolescence, January 2013.
4.  Danner F and Phillips B (2008) Adolescent sleep, school start times and teen motor vehicle crashes,Journal of clinical Sleep Medicine, 4, 533-535

Sleep during teenage years influences emotional and physical health

The quality and amount of sleep during adolescence remains a neglected research topic in the UK while the importance of sleep for adolescents’ well-being is widely acknowledged.¹ Some HBSC countries have already included questions on sleep in their questionnaire, and we have decided to include sleeping questions in England in the next round of HBSC.

Research suggests that optimal sleep duration for adolescents is 9 hours or more, with anything less than 8 hours considered to be insufficient. Both biological and social factors influence the duration of sleep: biological maturation, decreased parental influence, increased academic obligations and workload, social activities etc.² An insufficient amount of sleep can cause a lot of daytime stress to young people. Not getting enough sleep produces higher levels of anxiety, depressive feelings, excessive daytime tiredness and fatigue³.  Research also shows that insufficient sleep influences adolescents’ emotional, social and psychological well-being and can produce emotional, cognitive, and behavioural problems, a higher risk of depression and even suicidal thoughts⁴. Recent studies have found that a delayed sleep schedule can be correlated with low self-control, a tendency to postpone tasks and poor time management.³ Better-rested young people usually have higher achievement motivation compared to those who do not sleep enough. 

Sleep difficulties may also have an impact on adolescents’ functioning at school, since sufficient sleep is important for learning and cognitive performance.  School-based surveys indicate that adolescents who sleep less than others achieve lower school grades.^4,5,6 Students with sleep duration of less than 8 hours have been shown to exhibit more daytime tiredness, less behavioural persistence, less positive attitude towards life, and lower school grades in mathematics and languages compared to their counterparts who sleep longer.^2,4

Adolescents also have their own individual  circadian preferences: adolescents who  function better at evening/night time (people commonly referred to as owls) go to bed and wake up later (especially on weekends), spend less time in bed during the week but more on weekends, have irregular sleep–wake schedules, and report poor sleep. Moreover, evening types nap more frequently during school days, often complain of daytime sleepiness and inability to concentrate, have poorer school achievement, more injuries and were more emotionally upset than the morning types (people who would prefer to function from early morning, so called larks). Evening types also used more caffeine-containing beverages and substances to resist sleeping in the day time.^7,8

So how to improve adolescent sleep? Researchers recommend that young people strive to attain a sleeping duration of at least 8 hours.^{2, 5, 9}  Another recommendation is the development of interventions to reduce screen-based behaviours in the pre-sleep period, as it has been found that screen sedentary time (watching TV etc.) dominate adolescents’ pre-sleep period and this is associated with a later sleep onset.¹⁰ Recent research also suggests that a later start time for schools can be beneficial for young people’s well-being; this will be looked at more in-depth in our next blog post.

                                                                                                  

                                                Ellen Klemera

1. www.ayph.org.uk
2. National Sleep Foundation. (2006). Sleep in America poll. Washington DC: National Sleep Foundation
3.   Fuligni,A.J., and Hardway,C.(2006) Daily Variation in Adolescents’ Sleep,Activities, and Psychological Well-Being), Journal of Research on Adolescence , 16(3), 353–378.

4. Perkinson-Gloor ,N., Lemola,L., Grob,A.(2013) Sleep duration, positive attitude toward life, and academic achievement: The role of daytime tiredness, behavioral persistence, and school start times, Journal of Adolescence, January 2013.
5. Wolfson, A.R., Carskadon,M.A.(2008)Sleep Schedules and Daytime Functioning in Adolescents. Child Development, Volume 69, Issue 4, pages 875–887.
6. Dewald, J. F., Meijer, A. M., Oort, F. J., Kerkhof, G. A., & Bogels, S. M. (2010). The influence of sleep quality, sleep duration and sleepiness on school performance in children and adolescents: a meta-analytic review. Sleep Medicine Reviews, 14, 179–189.
7.  Howell, A.,Digdon, N.L., Buro,K., Sheptycki,A.R.(2008), Relations among mindfulness, well-being, and sleep, Journal of Personality and Individual Differences 45 (2008) 773–777.
8. Gianotti,F.,Cortesi,F., Sebastiani,T.,Ottaviano,S.(2002)Circadian preference, sleep and daytime behaviour in adolescence(2002),Journal of Sleep Research, Volume 11, Issue 3, pages 191–199, September 2002.
9. Owens, J. A., Belon, K., & Moss, P. (2010). Impact of delaying school start time on adolescent sleep, mood, and behavior. Archives of Pediatrics & Adolescent Medicine, 164, 608–614.
10.   Foley,L.S.,Maddison,R.,Jiang,Y.,Marsh,S,.Olds,T.,Ridley,K.(2013)Presleep Activities and Time of Sleep Onset in Children, Pediatrics Vol. 131 No. 2 February 1, 2013 pp. 276 -282 (doi: 10.1542/peds.2012-1651.