In the late 1600s John Locke who was an English philosopher and physician wrote many influential essays, one in particular titled: Some Thoughts Concerning Education 1. Here Locke describes the importance of cultivating good sleep habits in early childhood and its relationship health and development. Four centuries later these thoughts still remain true, and an abundance of scientific evidence is proving the associations between sleep and education among both children and adults.
The fundamental requirements for healthy growth in children are; (a) care and protection by parents/guardians; (b) adequate nutrition; (c) and adequate sleep. The first two requirements are quite obvious and will show physically in a child such as malnutrition. However mild to moderate sleep deprivation goes unnoticed in children, and has insidious effects on growth, development, and ultimately school performance. Adolescents will require on average between 8 and 9 ¼ hours of sleep depending on their age each night to function at their best the next day 2. Recommended sleep times chart according the National Sleep Foundation, USA can be viewed online via the following link: http://goo.gl/SXOnnx.
Adolescence as defined by the World Health Organisation is the period in human growth and development from ages 10 to 19. It is a transition from childhood to adulthood which includes both physical and mental maturation. Adolescent health is of such importance to society that in 2013 the Lancet, a prestigious medical journal published a report titled: Our Future: A Lancet Commission on adolescent Health and Wellbeing 3. It brought together experts from health, social, political, and economic backgrounds to consider strategies to advance adolescent health and wellbeing (http://adolescentsourfuture.com).
Individuals (young or old) may have difficulty functioning normally after a night of poor sleep, be it due to quantity or quality. So what makes sleep so important for adolescent students? A good night’s sleep is not only important to stay awake in class; in fact a sleep deprived student will exhibit memory impairment, deficit of attention, and a lack of concentration which would have dire consequences on their academic performance. A team of Swedish scientists demonstrated these problems with evidence from a large research study among school children in 2014; their conclusion being that poor quality of sleep, and short sleep duration are associated with academic failure among adolescents4. In fact two studies done in Israel5 in 2003 and Canada6 in 2013 revealed that a reduction in just one hour of sleep among school children aged 8 to 12 years resulted in increased daytime sleepiness, fatigue in the evening, difficulty regulating emotions, and impairment in performance in short-term memory tasks, math fluency and attention. Thus it is evident that sleep plays an important role in adolescent scholastic performance.
Although it is evident that regular and ample sleep is necessary, maintaining healthy sleep habits however are difficult during adolescence. This is due to biological changes that take place in the body during puberty through mechanisms that are not well understood yet. These changes trigger a forward shift in the sleep and waking times of the body’s internal clock; referred to as a ‘phase delay’. During and after puberty the phase delay will cause the body to feel sleepy later than usual; teenagers will find it harder to fall asleep at the usual time at night, and onset of sleep may be delayed. Therefore they will feel tired when they wake up in the morning to go to school, as they are unable to get the optimum amount of sleep each night. The magnitude of this delay increases from younger adolescents to older adolescents, and reverses during the early twenties.
In some adolescents a condition known as Delayed Sleep Phase Syndrome (DSPS) occurs which exaggerates the sleep phase delay by 2 or more hours. These adolescents usually fall asleep after midnight and have trouble waking up in the mornings, and the condition may continue into young adulthood. Adolescents and young adults with DSPS consider themselves night owls and are able to function better and remain alert during the late evening and night. The most common method of treatment for DSPS is to gradually go to bed earlier and scale back the sleep time until the normal sleep wake times are achieved.
It is important to note that adolescents with DSPS are able to maintain their sleep schedule as long as it does not interfere with daily routines and social obligations. Once they try to wake up early to synchronise with the everyday schedules of for example school; sleep deprivation will result as a consequence. For adolescents and young adults who’s DSPS interferes with their lives it is then termed Delayed Sleep Phase Disorder. The treatment once again would begin with early sleep schedules and managed with medication if necessary.
Two separate scientific journal articles which analysed results from different research studies on sleep conducted in different countries revealed that Asian older adolescents go to bed later thus obtaining less sleep than their North American and European counterparts; resulting in increased day time sleepiness 7,8. In this day and age the demands on teenagers are enormous; combining early school times, extracurricular activities and tuition classes alone leave children with less sleep time and a mountain of homework. Teenagers begin to develop social lives which are enhanced with modern technology and social media which impact the amount of sleep they require. Therefore even though phase delay occurs as a natural process, it is important to maintain healthy sleep habits in order to avoid poor sleep times.
If a teenager is lacking sufficient sleep parents will notice that their child has trouble waking up in the morning, feels sleepy during the day, and sleeps for longer during the weekends. They may also notice poorer school performance, lack of concentration, irritability, and possibly aggression. It is difficult to determine optimum amount of sleep for adolescent. A simple individual method to decide on an optimal amount would be to determine if a teenager’s sleep duration during school days is equal to the duration on weekends. Longer sleep times during weekends would suggest that the child is not getting enough sleep on school days, and the body is compensating the sleep deficit by sleeping longer during weekends.
In conclusion it is important to identify adolescents with difficulty falling asleep at nights as it adversely affects health and school performance. If a teenager is suffering from delayed sleep phase parents will notice that their children have trouble waking up in the morning, become sleepy and irritable in the afternoons, and possibly a sudden drop in school performance. The issue can be rectified by maintaining strict bed times and wake times, and as importantly making the child’s bedroom an environment for sleeping by removing any electronic devices such as televisions, computers as noises and bright lights from electronic devices stimulate the brain and keep them awake. This is especially true of mobile phones and electronic tablet devices which encourage late night internet browsing and engaging in social media. Heavy exercise few hours before sleep and stimulating substances such as coffee should be avoided before bedtime. Sleep should be made a priority for children, and if problems persist it is best to get professional medical advice.
References
- John, L. The Works of John Locke in Nine Volumes. (London: Rivington, 1824). Vol. 8. http://oll.libertyfund.org/titles/1444
- Hirshkowitz, M. et al. National Sleep Foundation’s sleep time duration recommendations: methodology and results summary. Sleep Heal. 1, 40–43 (2015).
- Patton, G. C. et al. Our future: a Lancet commission on adolescent health and wellbeing. Lancet (London, England) 387, 2423–78 (2016).
- Titova, O. E. et al. Associations of self-reported sleep disturbance and duration with academic failure in community-dwelling Swedish adolescents: Sleep and academic performance at school. Sleep Med. 16, 87–93 (2015).
- Sadeh, A., Gruber, R. & Raviv, A. The effects of sleep restriction and extension on school-age children: what a difference an hour makes. Child Dev. 74, 444–455 (2003).
- Vriend, J. L. et al. Manipulating sleep duration alters emotional functioning and cognitive performance in children. J. Pediatr. Psychol. 38, 1058–1069 (2013).
- Gradisar, M. et al. Recent worldwide sleep patterns and problems during adolescence: a review and meta-analysis of age, region, and sleep. Sleep Med. 12, 110–8 (2011).
- Olds, T. et al. The relationships between sex, age, geography and time in bed in adolescents: a meta-analysis of data from 23 countries. Sleep Med. Rev. 14, 371–8 (2010).
Dr. Kaushalya Jayaweera