Contrary to popular belief, teenagers actually require more sleep than adults. The 24-hour sleep need in teens is 9-9.5 hours, falling midway between children and adults. Yet, one would be hard pressed to find many teenagers getting anywhere near that amount of sleep in the 1990's.

With earlier school start times, sports, extracurriculum peer-group activities, and after school jobs, most teenagers are "lucky" if they can manage 6.5-7 hours of sleep nightly on school nights, often "crashing" on the weekends -- sleeping 10-12 hours Friday and Saturday nights -- to make up for the accumulated sleep "debt" across the school week.

Sleep deprivation is not compensated for in real time, but rather in higher percentages of certain "obligatory," sleep stages -- stage 4 delta sleep and REM sleep. "Recovery" sleep from some amount of accumulated sleep deprivation tends to be very deep and intense -- resembling the sleep of childhood. Teens who "make up" a lot of sleep over the weekend, sleep through the morning and often finally wake up feeling "groggy" and a little disoriented due to the increased amounts of stage 4 delta sleep.

To complicate the situation further, there is a delay in the timing of the internal biological clock during adolescence which causes a similar delay in the timing of sleep onset. Thus, there is a natural tendency for teenagers to go to bed later at night and want to sleep through the morning.

Teens are alert through the evening hours, but groggy and sluggish during the early morning. They are "Owls," not "Larks." It is not known whether this delay in the timing of the biological clock during adolescence is a property of the clock during this stage of development or socially driven by lifestyle -- most likely it reflects both.

The conflict between high school schedules, the longer 24-hour sleep "need," and the biological clock "delay" in adolescence has resulted in a sleep "debt" crisis in the adolescent population of the 1990's. Although the 16-29 year old age group accounts for only about 25% of all licensed drivers in the United States, 66% of drowsy-driving automobile crashes occur between midnight and 8am in 16-29 year old -- primarily male -- drivers.

Teenage boys with the greatest extracurriculum time commitments are most likely to report falling asleep at the wheel. This subgroup includes the brightest, most energetic, and hardest working teens. In a survey of >3000 high school students from 4 public schools in the Providence, Rhode Island area, Wolfson and Carskadon (1996) reported a correlation between lower grades and shorter sleep times. They also noted that teenage boys with the shortest reported total sleep time at night suffered more physical injuries, while teenage girls missed more school days due to illness.

Unfortunately, in the United States, most middle-schools and high-schools open earliest, leaving afternoons for extracurricular activities, sports, and part-time jobs. Based on the body of sleep research now available on adolescent sleep patterns and daytime alertness, later start times have been instituted in parts of Minnesota.

Edina, Minnesota moved its start time to 8:30am and the Minneapolis public school district moved the start time for middle schools 2 hours later to 9:40am and 1 hour later to 8:40am for high schools. School administrators have been struck by the positive effects -- more alert, less irritable, engaged teens in the classroom with improved family relationships at home.

Parents note better attitudes towards school and a marked improvement in family dynamics with everyone around a breakfast table together in the morning, before heading off to school and work.

Sources: NCSDR/NHTSA 1997 Report, "Drowsy driving and automobile crashes - expert panel on driver fatigue and sleepiness. Wolfson, A.E. and Carskadon, M. (1996). "Early school start times affect sleep and daytime functioning in adolescents." SLEEP RESEARCH. 25:117 (Abstract). MSNBC - "Waking up to adolescent sleep habits," by Beth Frerking (Newhouse News Service), October 5, 1997.

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