10/01/2012 08:18 am ET Updated Dec 01, 2012

Back to School: Your First Assignment Is Getting More Sleep


The challenges of a new school year begin to enter the minds of students and parents around this time of year. Nobody wants to be set up for poor performance before the first bell even rings. However, poor sleep habits of elementary, middle and high school students are making them sluggish during the day, may hinder their success at school and will likely contribute to long-term health problems.

How much sleep do students actually need? There is some variability based on the needs of individual children. The generally established values are as follows:

Age (years) Total Hours of Sleep Typical Range
6 10.5 10-11
10 10 9.5-10.5
14 9.5 9-10
18 9 8.5-9.5

The subjective quality of feeling rested when waking up, or general sleep satisfaction, is difficult to quantify but may also impact performance. While most studies include imperfect and subjective metrics (such as subjective reports of sleep quality, variable measures of academic performance ranging from grade point average to teacher comments), the preponderance of data suggests that reduced total sleep time, erratic sleep schedules, poor sleep quality (difficulty falling asleep or waking up at night), and sleepiness during the day are all associated with poorer academic performance.[1],[2]

Most of these effects are small to moderate, with only modest correlation between grades and subjective sleep measures. Many other variables are likely to influence school performance including school size, family socioeconomic status, teacher salaries, school facilities, and student hours of employment, among others.

A large majority of students, especially those in middle school and high school, have a very hard time developing and keeping proper sleep habits. Adolescents and teenagers go to bed too late. Constant use of technology (Internet, television, text messages, etc.) and an "always plugged in" lifestyle contribute to many students' bedtime habits. There is increasing evidence that adolescents, particularly pubertal or post-pubertal teens, may have trouble falling asleep early enough to get adequate rest even if they are willing to try.

The explanation for this relates to a delay in circadian rhythm. The circadian clock in our brain drives many behaviors over the 24-hour daily cycle, one of which is when we sleep and when we are awake. If this clock dictates a late bedtime and late rise time (a so-called "delayed phase"), it is difficult to both fall asleep at night at a reasonable hour and get up in the morning in time for school. Why adolescents tend to have a delayed clock is just beginning to be understood.[3],[4]

Some students may have an actual sleep disorder. The common disorders in children and adolescents are insomnia and an extremely delayed circadian phase (as outlined above). Some students may have sleep apnea as well. These disorders can all affect sleep duration and sleep quality and contribute to poor performance during the day.

So, what can be done?

Promote consistent bedtime and wakeup routines. Children and adolescents should have enough time in bed to get the required sleep based on the numbers provided above. Consistent bedtime and wakeup time also promotes better sleep quality.

Turn off the light. Exposure to bright light in the evening tends to further delay the circadian clock making it more difficult to fall asleep at the desired bedtime. Softer lighting and less time in front of a computer screen is advisable in the evening.

Talk to a specialist. If the child or adolescent has consistent difficulty falling asleep or wakes up during the night with difficulty returning to sleep a physician's advice should be sought. This could be a true delayed sleep phase disorder or another type of insomnia. If there are signs that the student is sleepy during the day, the cause should be explored medically, particularly if the student appears to be getting adequate sleep at night.

As students get back into a school year routine, it is important to make sure everyone gets a passing grade in Sleep 101!

For more by Dr. David White, M.D., click here.

For more on sleep, click here.


[1] Wolfson AR and Carskadon MA. Understanding adolescents' sleep patterns and school performance: a critical review. Sleep Med Rev 2003; 7: 491-506.

[2] Dewald JF, Meijer AM, Oort FJ, Kerkhof GA, and Bogels SM. The influence of sleep quality, sleep duration and sleepiness on school performance in children and adolescents: A meta-analytic review. Sleep Med Rev 2010; 14: 179-189.

[3] Hagenauer MH, Perryman JI, Lee TM, and Carskadon MA. Adolescent changes in the homeostatic and circadian regulation of sleep. Dev Neurosci 2009; 31: 276-284.

[4] Crowley SJ, Acebo C, and Carskadon MA. Sleep, circadian rhythms, and delayed phase in adolescence. Sleep Med 2007; 8: 602-612.