January/February 2003
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Reviewed by Lynne Lamberg |
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Nearly 9 out of 10 high school students need an alarm clock or a parent to wake them on school days. Many doze in class. "The students may be in school," writes Mary Carskadon, a pioneer investigator of teen sleep, "but their brains are at home on their pillows." Carskadon's studies show teenagers need 9.25 hours of sleep each night for optimal daytime alertness, at least as much sleep as younger children require. Most teenagers, however, get only about 7 hours of sleep on school nights. A key culprit: high school starts too early for most teenagers, often as early as 7 a.m. Two decades ago, high schools typically opened at 8 a.m. or later in the United States as well as elsewhere around the world. Changes in the biological clock triggered by puberty make it hard for most teenagers to fall asleep before 11:30 p.m. or midnight. Secretion of the hormone melatonin, which promotes sleepiness, starts about an hour later in the evening in adolescents than in pre-pubescent children, and ends about an hour later in the morning, too. In this book, Carskadon, director of sleep and chronobiology research at E.P. Bradley Hospital, Providence, RI, and colleagues explore developmental changes in sleep in both humans and animals, social and cultural factors that influence bedtime, and stress, depression, and other psychological concerns that affect teenagers' sleep. Miriam Andrade and L. Menna-Barreto, for example, surveyed a group of 12- to 13-year-old Brazilian youngsters over 18 months, observing that delayed weekend bedtimes followed the onset of puberty. Nearly half of 99 high school students they queried in a second study complained of being sleepy in the daytime at least once a week. Studies in Australia, Japan, Italy, Finland, Israel, and other countries show similar findings. Roger Rosa points out that at least half of US high school students also hold paid jobs. Half of this group, that is, 1 in 4 of the nation's high schoolers, work for pay 20 hours or more each week. Add to that the 35 hours a week these teens spend on their supposedly primary job, attending school. Most adult workers who work a comparable amount of time complain of job stress and fatigue. Extended work schedules may undermine school performance or prompt students to take less challenging courses (thus diminishing lifetime work opportunities). These schedules also may boost the likelihood that teens will make mistakes or get hurt while at work, and drive while tired. For all the effort, teenagers earn little money. Most perform unskilled labor at minimum wages. They don't save their earnings for college or contribute to family income, either. Most spend what they make on clothing, car expenses, and entertainment. Sleep deprivation dampens mood, perhaps contributing to the short fuses and crankiness that often erupt in adolescence. Teenagers who average less sleep than their peers use more caffeine, alcohol, cigarettes, marijuana, and other drugs, Amy Wolfson reports. Adolescence is a key time for integration of cognitive and emotional processing. Lack of sleep impedes maturation of these abilities, Ronald Dahl suggests. Depressed teenagers often replay mental tapes of real or imagined stresses at bedtime, Dahl says, further disrupting their sleep. Kyla Wahlstrom likens efforts to open high schools later to trying to alter the course of a supertanker ship: changes occur only by small degrees. Wahlstrom directs the School Start Time Study in the Minneapolis-St. Paul, MN, area. This comprehensive study has been assessing the impact of delaying the opening of high schools in that area, beginning with the 1997-98 school year. Researchers have surveyed students, teachers, parents, administrators, coaches, area employers of students, and others. The study shows that when school opens later, more students graduate, remain continuously enrolled, attend school more days, and more often show up on time. African-Americans, 40% of the total student population in Minneapolis, showed the most statistically significant positive gains. This wide-ranging book highlights problems that
adolescents suffer because they don't get enough sleep. It examines
reasons for this situation, and presents strategies that may help
remedy it. Parents, teachers, school board members and other lay readers
will find the text largely accessible, even sections that report findings
from basic science. This book is a stellar resource for those working
to change school start times in their communities as well as for the
broader community concerned with optimizing adolescent health.
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© 2003
WebSciences and Lynne Lamberg |
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