By Janis Graham
If your teen is a night owl and struggles to get up in the morning, he has plenty of company: Almost 80 percent of adolescents don't get the recommended amount of sleep, reports a recent National Sleep Foundation poll. Sleep-deprived teens aren't just cranky; they're also more likely to get poor grades, feel depressed, and-perhaps scariest of all-fall asleep behind the wheel.
The ideal amount of sleep for kids ages 11 to 17 is between 81/2 and 91/4 hours a night. That may sound like a lot, but there is plenty that parents can do to help their kids get enough rest, says Mary A. Carskadon, Ph.D. As director of the Chronobiology and Sleep Research Laboratory at Bradley Hospital in East Providence, Rhode Island, she co-chaired the National Sleep Foundation's 2006 Sleep in America Poll for children ages 11 to 17. She is also a professor of psychiatry and human behavior at Brown Medical School, where she studies the causes of daytime sleepiness in teenagers. Here, Carskadon answers questions about the unique sleep problems of teens and tweens.
Parents would know if their teens were getting too little sleep, right?
Not necessarily. It's surprisingly easy to misinterpret the cues. For instance, a top sign of lack of sleep is irritability-yet many parents may think, All teens are moody and difficult. In fact, as many as half of the teenagers we study are so sleep deprived they look as if they have narcolepsy, a serious neurological disorder that leaves people excessively tired. One of the worst consequences of this is car accidents. A major North Carolina study of crashes caused by the driver falling asleep behind the wheel found that about half involved a driver under age 25. Plus, kids who are sleepy are more likely to drift off in class, miss school entirely, and have trouble with learning and remembering. In some cases, a teen's mood disorder is a direct result of poor sleep.
Why do teens get so little sleep?
The onset of puberty is partly to blame. It changes a child's sleep timing system, also called the circadian system, which triggers the secretion of melatonin, the hormone associated with sleep. As kids mature, melatonin is secreted later and later in the evening. At the same time, during adolescence there's a slowdown of the "sleep pressure" rate-the rate at which sleepiness builds up over the course of the day. This also makes it easier for teens to stay awake longer and later.