Some educators say teens would benefit from a later start to the school day. (Eric Gay, AP)

The author is a Toronto-based freelance writer.

Most people complain about their teens' sleeping habits and shake their heads. Toronto school trustee Cathy Dandy, a mother of two teens, is one of them.

"With my older son and now my daughter, it's a battle," she says. "I've tried everything from tickling, shouting and bribing, to figuring out if there's anything happening that day that would give them the incentive to get up. It's just constant badgering."

In 2006, the U.S. National Sleep Foundation released a poll showing only one in five teenagers was getting enough sleep at night. While teenagers need about nine hours of sleep nightly, the poll showed that kids in Grades 11 and 12 were getting about 6.9 hours. (George Nikitin, AP)

But Dandy has a plan she thinks may help solve those early morning battles. Instead of trying to figure out new ways to get her teens out of bed bright and early for school each day, in October 2007 she persuaded her fellow trustees to consider later start times for classes.

She says a high school in the east end will be chosen for a pilot project in which classes would run from 10:30 a.m. until 4:30 p.m. Dandy is hoping the project will take effect next year.

Teenagers' sleep habits — particularly their penchant for sleeping in — have long been considered simple laziness by many, but researchers say that's not the case. In 2006, the National Sleep Foundation in the U.S. released a poll showing only one in five teenagers was getting enough sleep at night.

Mary Carskadon, a leading authority on teen sleep who chaired the poll task force, says the causes are both biological and behavioural.

"The circadian timing system, or daily clock, gets reorganized, pushing sleep to occur at a later time," she says. "The marker we use for the clock is melatonin secretion."

From the onset of puberty until the late teen years, melatonin (produced by the body to induce drowsiness) is secreted later in the evening. This could partly explain why so many teens can party the night away — and have trouble getting up early in the morning.

The other biological process affecting sleep patterns is that it's easier for teenagers to stay awake. While younger kids find it hard to resist sleep once they start to get tired, teenagers' bodies can easily fight that feeling. And when they decide to fight it, they have lots of ways to keep themselves busy.

Carskadon says, "The biological system is set up for later [periods of wakefulness], then you throw in all the things they have available in their bedrooms: TV sets, computers and gaming systems. When kids get involved in these things in the evening they're giving their biological systems the message that it isn't night yet. That's how some kids get stuck in these very late [sleep-pattern] times."

While teenagers need about nine hours of sleep nightly, the poll showed that kids in Grades 11 and 12 were getting about 6.9 hours. That lack of sleep was creating problems, ranging from a depressed mood and behavioural problems to falling asleep while driving.

While the Toronto Board of Education's plans are relatively new to Canada, later-starting school days were tried by educators in some regions in the United States beginning in 1999. These regions have stuck with them because they were so successful.

At that time, research showed that 20 per cent of teenagers were sleeping in class. Kyla Wahlstrom, director of the Center for Applied Research and Educational Improvement, explains that two Minneapolis school districts moved their start times from 7:15 and 7:20 a.m. to 8:30 and 8:40 a.m., respectively.

At first, there was resistance, but it soon eased.

"People thought it would affect afterschool sports and jobs, but we found after a year it didn't have a negative impact," Wahlstrom says. "Coaches came to love it because students were more alert."

In fact, says Wahlstrom, there was a clear difference in their performance. "Students said they were more awake in class, showed up with completed homework and reported less depression. Teachers felt the students were more alert for their first two classes in the morning, principals said there were fewer fights in the cafeteria and even parents said their kids were easier to live with. The positives were remarkable."

Dandy says in Toronto, the idea is taking hold, but slowly.

"There are two camps. The majority of parents are happy we're thinking of this, as are people in the educational system familiar with the research," she says. "Then there's the smaller camp that walked to school in 40 feet of snow [in their day]. I received one scathing e-mail informing me I was creating a generation of late-shift workers."

For some teens, says sleep expert Carskadon, the problem can become very serious. Some teens are ending up with "delayed sleep phase disorder" — going to sleep very late and being unable to rise in the morning. "It becomes devastating for their lives."

Sometimes they can be treated using chronotherapy, which involves later sleep- and wake-times each day until the person's body clock is moved to a suitable timeframe.

One factor that exacerbates the problem of teen sleepiness is how teens make up their 'sleep debt' on the weekends, Carskadon adds. "If they sleep in well into the day, they're giving their body the signal that nighttime is even later. Then Monday comes and they're stuck in an even worse position."

Carskadon says attitudes towards sleep need to change.

"It's a public health issue, and if no one is ever taught anything about it, nobody believes it's important," she says.