Schools fix hours for sleep-deprived teens

Valerie Strauss / Washington Post

It's 10:45 p.m. and the light is still on in your teenager's bedroom. Your child is not the slightest bit tired -- but you know that waking him or her early for school the next morning will be torture.

It may be tempting to blame this behavior on computers, cell phones and coffee. And, in some cases, those are the prime reasons for nocturnal teen behavior.

But, researchers say, this late-to-bed and late-to-rise pattern is the way teenagers are biologically programmed -- even though most school systems gloss over this when setting high school start times.

Some districts have respected the science enough to give teens more sleep-in time -- and researchers have found a number of benefits, including improvements in attendance and daytime alertness and decreased depression.

But most school districts cite sports and other activities, bus routes and other scheduling issues as reasons for starting between 7 a.m. and 8 a.m.

Seven hours not enough

As a result of these early start times, most teens don't get the 8 1/2 to 9 1/2 hours of sleep that experts say they should, according to the National Sleep Foundation. In fact, the average is about seven hours of sleep a night for teens.

Watch exhausted teens walk into their high school on any given morning, eyes half-closed with coffee cup in hand, and you can see the scope of the problem. A Drexel University study found that only 20 percent of 12- to 18-year-olds studied got the recommended amount of sleep on school nights.

Researchers over the past decade have learned that a teen's body is different than those of younger and older people. Most teens can't easily fall asleep until about 11 p.m., experts say, and their brains stay in sleep mode until at least 8 a.m.

A study led by Brown University Professor Mary Carskadon tested the saliva of teens, measuring the presence of the sleep-promoting hormone melatonin at different times of the day.

Carskadon, who teaches human behavior and is director of sleep research at E.P. Bradley Hospital in Rhode Island, found that melatonin levels rise later at night than they do in children and adults -- and remain higher later in the morning.

Why melatonin is secreted in the teenage brain from about 11 p.m. until about 8 a.m. the next morning is unclear, experts say.

Some school systems around the country have taken heed of the research findings and moved to start high school at later times. Pioneers were two Minneapolis-area school districts -- Edina, a suburban district that changed its start time from 7:20 to 8:30 a.m. in the 1990s, and then Minneapolis Public Schools, which changed the start time for thousands of high school students from 7:15 a.m. to 8:40 a.m. in the 1997-98 school year.

The effects were studied for several years by researchers at the University of Minnesota's Center for Applied Research and Educational Improvement, led by director Kyla Wahlstrom. They found that students were more alert and students reported higher grades (though how much higher is unclear).

Since then, more than 80 school districts have changed their start times, according to the sleep foundation, including the Arlington, Va., public schools, which gave high school students 45 extra minutes to sleep starting in 2001. No studies were done on the effects but students reported being more alert.