Many teens are sleep deprived, according to the National Sleep Foundation. The NSF reports 60 percent of children under age 18 are tired during the day and 15 percent fall asleep in class. It’s not that they’re lazy. Teens’ biology affects their ability to fall asleep early enough to get a full night’s sleep. School start times -- especially when schools begin classes during the 7 a.m. hour -- can make the problem much worse.
Teen Sleep Patterns
Teenagers need about 9 1/4 hours of sleep every night, according to the NSF. Yet once school starts, most teens lose two hours of sleep each school night, according to a document compiled by South Orangetown Central School District (SOCSD) in New York, entitled "The Impact of School Start Times on Adolescent Health and Academic Performance." Although teens can be their own worst enemies -- cramming jobs, sports, homework and social activities into their schedules, drinking caffeine and staying up late to email or play online games -- even when they try, most teens can’t fall asleep before 10 p.m. or later. In addition, the sleep-promoting hormone melatonin is still high when most teens arrive at school.
Early school start times result in teens who are still sleepy, because they have not had enough sleep to feel rested. Sleep-deprived teens cannot learn as well and cannot remember what they’ve learned, according to SOCSD. In addition to impaired learning capacity, sleep-deprived teens are more susceptible to depression, anxiety and fatigue, have decreased athletic and motor skills and may be at higher risk for alcohol and drug use. Lack of sleep also affects teens’ secondary brain development.
Later Start Times
Later school start times can have an effect on teens’ academic performance, behavior and safety, according to the NSF. Beginning in 1996, high schools in Edina and Minneapolis, Minnesota changed school start times to 8:30 a.m. and 8:40 a.m. respectively. Three years later, both schools showed improved attendance, less tardiness and increases in continuous enrollment. Students reported they got an average of one more hour of sleep and were more likely to be able to do their homework in class because they were more alert. Grades showed a slight improvement, student behavior improved in suburban schools and there were fewer disciplinary referrals. An experiment in Massachusetts in 2004 showed similar results.
Teen Driving Accidents
School start times can affect automobile accident rates among teen drivers, according to a June 2010 article in "U.S. News Health." Studies in Virginia Beach and Chesapeake, Virginia, showed that in Virginia Beach, where high schools start at 7:20 a.m., there were 65.4 car crashes per 1,000 teen drivers. In Chesapeake, school starts at 8:40. Chesapeake’s crash rate was 40 percent lower than the rate in Virginia Beach. Another study reported in the December 2008 "Journal of Clinical Sleep Medicine" found teen driver crash rates dropped more than 16 percent when high schools started one hour later.