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TEENS, SLEEP AND SCHOOL STARTING TIMES: WHAT WE KNOW
• Teens sleep needs and what they get
• Consequences of sleep deprivation
Teens sleep needs and what they get
• Teens need 8.5 to 9.25 hours of sleep in order to be alert–as much or more than they got as children! (Carskadon et al, 1980).
• Why not go to bed earlier? The biological clock of pre-teens shifts forward, creating a “forbidden zone” for sleep around 9 or 10pm.Due to changes in biological clock with adolescence, studies show that the typical high school student’s natural time to fall asleep is 11PM or later (Wolfson and Carskadon, 1998)
• Why not sleep late on weekends? Sleeping late on weekends can be destructive because teens can’t fall asleep on Sunday night and start the week more in debt than ever. (Carskadon interview)
• With buses picking kids up as early as 6:30 AM, students simply cannot get the amount of sleep they need. Around the country, teens are getting 7.5 hours on average. Bethesda-Chevy Chase teens get 6.5 hours, Walter Johnson teens get 6.8 hours (WAKE UP! 2001 and 2002).
Consequences of sleep deprivation
Reduced school performance
• Sleep deprivation reduces attentiveness and ability to learn. When teens had 8 hours sleep, they got better and better at assigned tasks. With 6 hours over several nights, the learning curve became flat, and at four hours, subjects became less and less able to perform (Dinges).
• High school students who describe themselves as having academic problems and who are earning C’s or below report getting less sleep, having later bedtimes and having more irregular sleep schedules than students reporting higher grades. However, a causal relationship has not yet been established. (Wolfson and Carskadon, 1998)
• 60% at WJ and 65% at BCC have trouble staying alert in class one or more times a week! (WAKE UP!, 2001b and 2002)
• 44% of WJ students and 33% of BCC students fall asleep in class one or more times per week (WAKE UP!, 2001b and 2002).
• 46% of WJ students and 38% of BCC students don’t finish homework one or more times per week because of being tired. 64% at BCC and 72% at WJ don’t finish their homework at least once a month due to fatigue. (WAKE UP!, 2001b and 2002).
Lateness and absenteeism
• 22% at WJ and 9% at BCC come to school late one or more times per week because of oversleeping, another 22% at WJ and 14% at BCC one to three times per month. (WAKE UP!, 2001b and 2002).
• 17% at BCC and 15% at WJ miss school at least once a month due to fatigue. At WJ, 50% miss school every few months or more because of tiredness. (WAKE UP!, 2001b and 2002).
Driving crashes
• A recent study suggests that changing school start times to an hour later in the morning could make a difference in the rate of teen car crashes. Fred W. Danner, PhD, of the University of Kentucky, examined auto collision statistics in Fayette County, KY, where the school district changed high school start times from 7:30 to 8:30 a.m. In the following year, students averaged up to 50 minutes more sleep per night. Dr. Danner found that crash rates for 16-18 year olds dropped following the change, while crash rates for 17-18 year olds increased in the rest of the state.
• WJ: Of the 42% who ever drive to school, 10% drive drowsy one or more times per week and 9% 1-3 times per month!
Emotional and behavior problems
• New epidemic of depression among teens, probably caused in part by sleepiness (Public Broadcasting Service). Sleepiness has also been associated with difficulty controlling emotions, impulsivity, and aggression. (Wolfson and Carskadon, 1998, Dahl, 1999, Wolfson et al, 1995).
• Increased use of stimulants like caffeine, nicotine, and alcohol. (Carskadon, 1990).
Increased opportunity for risky behaviors due to lack of supervision in afternoons
• On school days, 45% of juvenile crime occurs between 2 and 8PM with sharpest rise between 2 and 4 PM (Wahlstrom and Freeman, 1997; Center for the Study and Prevention of Violence, 1998).
Health
• Van Cauter’s research shows that lack of sleep in healthy young people causes many of their hormone systems to malfunction. Growth hormones, for instance, which are important for tissue repair and growth, decrease. The stress hormone cortisol also increases during the night when it should decline, potentially endangering brain cells. And insulin, which is critical for metabolizing food, no longer does its job properly. When insulin has a tougher time converting glucose from the food we eat into energy or fat, the body has to make two to three times the normal amount. This is a condition called insulin resistance, and it is now believed to be the first step on the way to type 2 diabetes. At the same time, leptin, a hormone that normally tells your brain that you're full and that you should stop eating, declines, making you hungry and wanting to eat more.
Family stress (anecdotal data)
Starting times
Among the Nation’s 25 most populous school districts:
• 13 start later than MCPS
• 4 start earlier than MCPS
• 7 start about the same time as MCPS
Local Systems’ High School Start Times
• D.C. 8:30
• P.G. 8-9:30
• Frederick: 8:00
• Howard 7:30
• Fairfax 7:20
Area Private Schools:
• St. Andrews 8:25
• Field 8:20
• Georgetown Prep 8:15
• Holy Cross 8:10
• Holton Arms 8:10
• Sidwell 8:00
• Sandy Spring 8:00
• Bullis 8:00
Minneapolis
• 1997-1998 high school start time shifted to 8:40 AM from 7:15 AM.
• 1998 study using student and teacher surveys, focus groups with students, teachers, administrators, interviews with coaches, activity directors, employers:
• students getting one hour more of sleep per school night
• students reported significantly less sleepiness
• students and teachers reported fewer classes missed and less sleeping in class during periods 1 and 2
• students reported less depression compared to peers in another district
• counselors noted drop in self referral for depression and peer problems
• 2001 study: 1995-2000
• - significant improvement in attendance and continuous enrollment in school or district
• - slight improvement in grades, not statistically significant. However, there were major problems in doing this analysis, e.g. classes had different names in different schools; variation in length of class periods and number of grading periods missing data; duplication where one student counted more than once.
Arlington
• Moved high school start time from 7:30 to 8:15 this academic year. There was no exodus of teachers because of school start times but we don’t have any data on student impact yet.
Other Lessons from BCC and WJ Surveys
• Most frequent transport: WJ: 42% take bus, 34% drive, 22% parent drop-off
Student opinion
• BCC: 82% favored later school starting times
• WJ: only 29% prefer current starting time, 51% want later start time, 17% unsure.
Parents: 200 addresses are on the WAKEUP! e-mail network–just the tip of the iceberg!
Bottom line: WE ARE RISKING OUR CHILDREN’S HEALTH AND JEOPARDIZING THEIR ABILITY TO LEARN Click here to learn what you can do
References (click on blue underlined titles to go to article)
Carskadon, Mary. 1990. “Patterns of sleep and sleepiness in adolescents.” Pediatrician.
Carskadon, MA, Harvey, K., Duke, P., Anders, TF, Litt, IF, Dement, WC. 1980. “Pubertal Changes in Daytime Sleepiness,” Sleep 2: 453-460.
Center for the Study and Prevention of Violence. 1999. Youth Violence: A Public Health Concern. Fact Sheet 9. June.
Dahl, R.E. 1999. “The Consequences of Insufficient Sleep for Adolescents: Links Between Sleep and Emotional Regulation.” Phi Delta Kappan: 354-359.
Danner, Fred, Paper prepared for presentation at the Associated Professional Sleep Societies' Annual Meeting in Seattle, June 8-13, 2002.
Dinges, David, M.D. (UPenn) as quoted in Marc Kaufman, “Sleepless in Suburbia: Why does high school have to start so early in the morning?” The Washington Post Magazine. February 25, 2001.
Public Broadcasting Service, Interview with Mary Carskadon
Kotulak, Ronald, “Waking Up to the Danger of Sleep Deprivation,” Chicago Tribune, May 27, 2001
Wahlstrom, Kyla L., Davidson, Mark L., Choi, Jiyoung, Ross, Jesse. 2001. School Start Time Study: Executive Summary. Minneapolis, MN: University of Minnesota, Center for Applied Research and Educaitonal Improvement.
Wahlstrom, K.L. and Freeman, C.M. 1997. School Start Time Study: Final Report Summary. Minneapolis, MN: University of Minnesota, Center for Applied Research and Educational Improvement.
Wahlstrom, K., Wrobel, G. and Kubow, P. 1998. Minneapolis Public Schools Start Time Study: Executive Summary. Minneapolis, MN: University of Minnesota, Center for Applied Research and Educational Improvement.
WAKE UP! 2002. Walter Johnson survey results.
WAKE UP! Sleep Deprivation is Widespread at BCC High School. 2001.
WAKE UP! 2001b. Unpublished Data from BCC Mail-in Survey.
Wolfson, AR, Carskadon, M.A., “Sleep Schedules and Daytime Functioning in Adolescents. Child Development 1998 (69): 875-887.
Wolfson, R., Tzischinsky, O., Brown, C., Carley, C., Acebo, C., and Carskadon, M.A. 1995. “Sleep, Behavior, and Stress at the Transition to Senior High School.” Sleep Research 24.
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page last updated 12-28-02