Can't get your teen out of bed to go to school? Maybe the problem isn't him. Maybe the problem is his changing body. As adolescents grow, their sleep cycles change (Carskadon, 1999). During adolescence teens tend to stay up later and sleep later. Some of these changes are explained behaviorally by increased academic loads, increased extra-curricular activities, employment schedules, and socializing (e.g. parties and texting). But some of the changes are due to intrinsic, biological changes. Even more seriously, researchers, doctors, and teachers are realizing that circadian rhythms and school schedules are out of synch (Carskadon, 1999). The result is excessive sleepiness, inferior academic performance, and even accidents.
Pioneering research has begun to focus on circadian rhythms and circadian rhythm disorders (Carskadon, 1999). Circadian rhythms are internal, biological "clocks" with oscillations in alertness and sleepiness over a 24 hour cycle. Their center is deep in the brain, in the hypothalamus, and triggered by light. Measurable by biological events, like melatonin, circadian rhythms control the timing of rapid eye movement sleep (REM). Research is beginning to show that circadian rhythms are developmental and change with growth from childhood, to adolescence and adulthood (Carskadon, 1999).
Early survey research at Stanford University, showed that as pubescent girls matured they preferred evening to morning schedules (Carskadon, 1999). In other words, as the girls' bodies changed so did their sleep cycles. This is more than staying up late to have fun. Changing sleep cycles are biologically based. Furthermore, parent surveys and teen sleep diaries indicate that during the school year, teens average about 2 hours/per night less sleep than in the summer. The effect is cumulative. So losing 2 hours sleep each night adds up to a total of 10 hours lost sleep by the end of the week. As adolescents' bodies change, they stay up later but still show afternoon dips in alertness. Previously believed to be a sleep pattern of younger children, who once took naps in school, this "siesta" effect is pronounced even into later adolescence. Changing circadian rhythms of adolescent bodies and early school schedules are out of sync. In extreme cases, the teen may even develop a clincial disorder called delayed sleep phase disorder (http://emedicine.medscape.com/article/1188944-overview). Teens are sleepy and with good reason. They are not getting enough sleep. And, this has serious implications.
So what is the suggested amount of sleep for kids and teens? According to Dr. Valerie Crabtree at St Judes, Memphis, TN, children aged 3 to 6 years ideally need 11 hours of sleep in a 24 hour period but are getting about 9 hours. The ideal number of hours of sleep for 6 to 12 year olds is 10 hours but parent surveys show that most are getting 8 to 9 hours. For 12 to 14 year olds, 9 hours is recommended but 8 hours is closer to reality. And, for 15 to 18 year olds, the ideal is 9 but most are getting about 7 hours during on school days during the week.
Face it. Our kids are tired and so are we. Hectic schedules, school, extra-curricular activities, and work place a lot of demands on us. We are all juggling a lot of societal demands. And, we are trying to meet these demands by taking the time from our sleep. But this concerns me. It concerns me for a lot of reasons. First, anybody knows that sleep deprived people are irritable and irritable parents are short with their kids. It is also no surprise that a clinical symptom of insomnia is "malaise." Tired people don't feel good and they don't perform well either. Sleep deprivation impairs academic performance. There is a lot of pressure on teens to perform in class and on standardized tests. But, sleepy teens fall asleep in class and fatigue interferes with test performance. Optimal performance can only occur when one is fully rested. Next, accidents occur when people are fatigued. Slowed reaction times can cause accidents on the football field, in wood shop, and even behind the wheel. And... finally, serious sleep deprivation not only makes people crabby with each other, limits optimal academic performance, increases accidents, but ultimately might even interfere with healthy physical growth and development.
Carskadon, M. A. "When Worlds Collide: Adolescent Need for Sleep Versus Societal Demands, " Phi Delta Kappan, Vol. 80, No. 05, Jan. 1999, pp.348-353.