Teens tend to be in their deepest sleep around dawn when they typically need to get up.  Some might just be getting to bed, but that’s another story. Because the melatonin cycle is time shifted by at least two hours in teens, going to sleep before 11 p.m. is unheard of.

No wonder they’re cranky and rebel! Sleep deprivation is a form of torture. I don’t know anyone who ever got up for school who wouldn’t have loved to sleep in an hour or two longer and get started, let’s say, around nine or ten. At least teens would get a boost from melatonin, the hormone that triggers sleepiness by taking full advantage of the sleep cycle.

Minnesota study

One of the first, longest-lasting and most influential teen sleep experiments started in Minnesota in the mid-1990s. Around that time, Minneapolis high schools shifted start times from 7:15 to 8:40. The nearby suburb of Edina shifted from 7:25 to 8:30.

Even though the two districts couldn’t be more different on scales of race, socioeconomics and other factors, results in both places appeared immediately, says Kyla Wahlstrom, director of the Center for Applied Research and Educational Improvement at the University of Minnesota, Twin Cities.

Students were noticeably more alert in the first two periods of the day. The cafeteria was calmer. There were fewer fights in the halls. Students, who were now getting nearly an hour more sleep each night, said they felt less depressed. They were raising their hands instead of falling asleep at their desks. Even parents thought their kids were easier to live with.

Over time, Wahlstrom and colleagues documented, students started getting better grades on homework and quizzes. Schools reported lower tardiness rates. Attendance rates went up. Graduation rates improved.

The Rhode Island study results confirmed the benefits of shifting the school start day by only30 minutes, to 8:30 a.m. – barbaric still, but the results were stunning none the less.

The portion of students reporting at least eight hours of sleep on school nights jumped from about 16% to almost 55%. It’s beginning to look like 10 a.m. isn’t such crazy idea after all. Maybe there’s something to say for being naturally alert.

Judith A. Owens; Katherine Belon; Patricia Moss
Arch Pediatr Adolesc Med. 2010;164(7):608-614.