Adolescents can list many reasons to stay up late–ranging from studies to part-time work, parties or even late-night TV, video games or the Internet.
"Many students deprived of sleep show less control over their emotions, crying readily or becoming easily irritable or giddy."
Teenagers gathering on a dark street corner. It’s 6:30 a.m., and they are exactly where their parents and teachers expect them to be: waiting for the school bus.
Mainly because of bus scheduling, many high schools today start at 7:30 a.m. or earlier–long before the sun rises on a cold winter morning. Adolescents, administrators argue, are better able than early elementary students to manage the early rising times. Moreover, they can devote the extra afternoon hours to extracurricular activities or part-time work.
The early starting time is just one of many factors conspiring to squeeze sleep time from American teenagers. Adolescents can readily list many reasons they have to stay up later, whether on week nights or weekends–ranging from studies to part-time work to parties or even late-night television, video games or the Internet.
Whereas younger children get a relatively stable 10 hours of sleep a night, after age 10 they find themselves steadily getting less sleep each year. According to one survey, high school students slept an average of 7.2 hours a night, with 26 percent sleeping less than 6.5 hours on week nights.
As a result, many American teenagers are simply not getting enough sleep. One study of more than 3,000 teens published in the Journal of the American Medical Association concluded that “85 percent were chronically sleep-deprived and accumulated a sleep deficit during the week.” This lack of sleep, some authorities argue, puts a child at risk not only of health problems but poor performance at school and a range of emotional and behavioral problems.
Moralists will argue, of course, that teenagers should simply get to bed earlier, but that is easier said than done. In addition to the pressures of school, extracurricular activities and part-time employment, teens are faced with physical changes that make it more difficult for them to get to sleep at an earlier time.
Adolescents seem to be particularly vulnerable to sleep disruptions caused by social stress, fear or anxiety. In addition, changes occur in the biological clock during adolescence, creating a natural tendency to fall asleep later and wake up later. One study indicated that secretion of melatonin, a hormone that prepares the body for sleep, occurs later and later in the evening as a child goes through adolescence and shuts off later and later in the morning.
How Much Sleep Is Needed?
Exactly how much sleep is needed, no one can say for sure, but sleep experts believe that 80 percent of Americans, regardless of age, don’t get enough. One study concluded that adolescents required 9.2 hours of sleep a night for best daytime functioning. “The amount of sleep students got was reflected in their grades,” the authors wrote. “Those who reported earning mainly A’s and B’s went to bed earlier on both week-nights and weekends than those who received D’s and F’s, and the high achiever averaged about 35 minutes more sleep per day than the low achievers.”
Sleep is not merely rest, but an active process that’s necessary for restoration of mind and body. Adequate sleep is essential to processing and storing carbohydrates and regulating the secretion of hormones.
Sleep is particularly important during periods when the brain is developing. In every species, individuals who are maturing require more sleep than those who are fully mature.
Studies have shown that both early slow-wave and late REM (rapid eye movement) sleep are crucial to memory and consolidation of learning. Growth hormone, essential to normal growth, is released throughout the day but apparently with a major pulse during REM sleep.
What happens to teenagers who don’t get enough sleep? Well, first of all they get sleepy. This doesn’t happen when they’re playing a video game or hanging out with friends but rather during times of low stimulation–when parents and teachers expect them to be alert.
Students with chronic sleep debt are likely to fall asleep frequently in class or while studying. They are also prone to brief lapses of attention or responsiveness, creating even more problems, whether in the classroom or behind the wheel of a car.
Adolescents who have trouble getting out of bed in the morning and to class on time are likely to have ongoing conflicts with parents and teachers. Those who resort to stimulants or nicotine in an effort to seem more alert only compound the problem.
The tiredness and lack of motivation that come from sleep deprivation might easily be mistaken for chronic fatigue syndrome. Similarly, the brief lapses of attention may mimic the symptoms of attention deficit/hyperactivity disorder (ADHD). In fact, ADHD is more common in children with sleep disorders, and both respond to treatment with stimulants.
When it comes to emotional and behavioral problems, it’s hard to sort out causes and effects. A child with depression or anxiety is likely to have problems getting to sleep, and the sleep loss may make the mood disorder worse.
It’s also possible that sleep loss could trigger mood disorders. According to one study, adolescents who got less than 6 3/4 hours of sleep on week nights were more likely than others to report symptoms of depression. In either case, there’s the risk of progressively worsening effects.
Individuals deprived of sleep show substantial variation in their reactions, but many young people tend to exhibit less control over their emotions. They may become irritable or angry when frustrated, cry more readily when things go wrong or become giddy or silly in humorous situations.
This loss of control over emotions might also put them at increased risk in situations involving aggression, alcohol or drug use, sexual behavior or unsafe driving.
What Can Be Done?
In response to the accumulating evidence, a few schools have taken action to set back starting times.
In 1996, Edina, MN schools moved the starting time for high school students from 7:20 to 8:30 a.m. The following year, seven high schools in Minneapolis moved their starting times from 7:15 to 8:40. Students from these schools reported getting at least a full hour more sleep each night with less daytime sleepiness, better mood and higher grades. Tardiness and absenteeism are down.
Some school districts in Kentucky and Maine have changed their starting times, but it’s unrealistic to expect large numbers of schools to follow suit.
Nevertheless, it’s important that adults understand the problem. Teachers should not assume that a sleepy or sleeping student is lazy, abusing drugs or trying to be rude. The teenager who sleeps late on weekends is probably trying to erase sleep debt incurred during the week, rather than trying to evade chores. It’s true, of course, that Sunday sleep-ins may make it even harder for the teen to get to sleep on Sunday night. And there’s some evidence that more regular sleep schedules are less likely to lead to mood disorders.
When daytime sleepiness is combined with behavioral or emotional symptoms, the student may have a sleep or mood disorder requiring prompt medical attention.
Gabrielle Brandenberger, et al, “Effect of Sleep Deprivation on Overall 24 Hour Growth Hormone Secretion,” The Lancet, October 21, 2000.
James Butcher, “Sleep Deprivation Impairs Memory Formation, Say Researchers,” The Lancet, December 2, 2000.
“Chronic Fatigue? Teens May Just Be Sleep Deprived,” Family Practice News, August 1, 1999.
Ronald E. Dahl, “The Consequences of Insufficient Sleep for Adolescents: Links between Sleep and Emotional Regulation,” Phi Delta Kappan, January, 1999.
Louis Kuritzky, “Sleep Debt on Metabolic and Endocrine Function,” Neurology Alert, February, 2000.
“Sleep Needs, Patterns, and Difficulties of Adolescents,” workshop September 22, 1999.
“Sleep Restriction May Cause Attention Problems,” Family Practice News, November 1, 2000.