Studies conducted over nearly a 30 year period have consistently shown only a small fraction of adolescents obtain the 9 or more hours (1) of sleep they require to function at their best. (2, 34, 5, 6, 7) In recent years, scientists have characterized the problem as “epidemic” in proportion. (8, 9) While teenagers are notorious for causing their own sleep difficulties—staying up too late, playing with electronic gadgets, and generally burning the candle at both ends— (10, 11, 12, 13, 14) sleep loss among adolescents is confined primarily toowl watching tv school nights. (2, 3, 4, 7, 8, 10, 15, 16, 17, 21, 22, 23, 24, 25, 26, 27Teens lose up to 3 hours of sleep on weeknights after the start of school. (4, 17, Mindell & Owens, Clinical Guide to Pediatric Sleep: Diagnosis and Management of Sleep Problems (Lippincott Williams & Wilkins, 2nd ed. 2010) p. 258.) 

More than 42 percent of U.S. junior and senior high schools begin before 8 o’clock, (28while the sleep-inducing hormone, melatonin, still pressures adolescents to sleep. (3, 31, 35, 36) The circadian system manages a sleep/wake cycle in adolescents that runs from approximately 11 p.m. to 8 a.m. (815, 3135, 37, 38, 39) The sleep pressure rate, or homeostatic drive—the biological trigger that causes sleepiness—slows down in adolescence. (3, 9)

“There is clear evidence for a phase shift during adolescence, with adolescents going to bed later and rising later than children. This phase shift is largely biological, with adolescents typically unable to fall asleep at earlier times.” (Coch, Fischer, & Dawson, Human Behavior, Learning, and the Developing Brain: Typical Development (Informa Healthcare 2010) p. 382.) “As with adults, the physiological factor that most powerfully regulates the timing of waking and sleeping in adolescents is the circadian rhythm, a hard-wired ‘clock’ in the suprachiasmatic nucleus of the brain.” (15

For most U.S. secondary students, circadian biology collides with early morning classes five days a week, (3, 4, 8, 10, 11, 15, 21, 22, 23, 38, 40, 45, 46leaving many “pathologically sleepy.” (4748Children “may feel adapted to being tired, but performance tests show the opposite.” (4950, 51) Researchers have found a “general ‘cloud’ of negative daily affect that is associated with chronic patterns of inadequate sleep among adolescents….” (52A 2005 study published in “Pediatrics,” the official Journal of the American Academy of Pediatrics, concluded, “School schedules are forcing them to lose sleep and to perform academically when they are at their worst.” (8)

Restricted sleep in adolescents is associated with profoundly impaired learning capacity, (10, 11, 22, 53, 54, 55, 56, 57, 58, 59, 60) increased rates of depression, anxiety, and fatigue, (11, 52, 64, 65) increased risk of suicidal ideation and completed suicide, (66, 67, 68, 69, 70, 71, 72increased rates of automobile accidents, (40, 75decreased athletic and motor skills, (76, 77) excessive weight gain, (78, 79, 80, 85, 86) increased likelihood of criminal conduct (90) and risk-taking behaviors, including drug or alcohol use, (71, 72, 9192) increased likelihood of physical, psychological, or social difficulties, (95, 96, 97) elevated blood pressure, (100) interference with secondary brain development, (105, 106, 107) etc.

The CDC, (108) the American Psychological Association, (109) and the National Institutes of Health, (5, 110, 111) have identified early school start times as a factor contributing to teen sleep deficiency. Janet Croft, Ph.D., a senior epidemiologist at the CDC, believes Mountain View HS senior and honors student Tyler Shankel -- 2009that early school start times have a “deleterious impact” and impose “an unrealistic burden” on adolescent students. (113) Stanford sleep expert William Dement, M.D., Sc.D., Ph.D., summarizes the problem this way, “Sending kids to school at 7 a.m. is the equivalent of sending an adult to work at 4 in the morning.” (114

In 1994, the Minnesota Medical Association wrote to every school superintendent in the state of Minnesota, requesting that administrators delay morning classes for adolescents. (117As a result, thousands of students had their school start times delayed from 7:25 a.m. to 8:30 a.m. (Edina) or later (Minneapolis, 8:40 a.m., high schools, and 9:10 a.m., middle schools). Researchers found that student health, well-being, and performance (including SAT scores), improved in every respect. (31106118Four years into the study, researchers found students in Minneapolis high schools continued to get 60 minutes more sleep on weeknights than did their peers whose school began at 7:30 a.m. (118) 

Following the Minnesota study, physicians from the Thoracic Society of Connecticut assembled a task force to both raise awareness and advocate for a change to later start times. (112, 115According to Dr. Heidi Connolly, Associate Professor of Psychiatry and Pediatric Sleep Medicine at the University of Rochester Medical Center in New York, “Sleep medicine specialists have long known that delaying high school start times helps teenagers sleep better.” (116)  

In 2009, a private Rhode Island high school changed start times from 8 a.m. to 8:30 a.m. at the urging of sleep medicine specialist Dr. Judith Owens.(119As in Minnesota, fewer depressive symptoms were reported among students following the change. (120) Researchers found this “particularly noteworthy[,]” given the relationship between depression and suicidal ideation in adolescents. (120) In addition, students reported feeling more motivated to participate in a variety of activities and were less likely to seek medical attention for fatigue-related concerns. (120) Following the change, students actually went to bed 15 minutes earlier, increasing their nightly sleep total by 45 minutes. (120) Despite resistance from faculty and athletic coaches before the change, students and faculty voted “overwhelmingly” to retain the 8:30 a.m. start time. (120)

In 2010, CDC scientists reported, “Delaying school start times is a demonstrated strategy to promote sufficient sleep among adolescents.” (3Kyla Wahlstrom, Director of the Center for Applied Research and Educational Improvement (CAREI), notes that in schools which have delayed start times, the academic trend following the change goes exclusively towards higher grades, (125) an assertion which appears well-supported by the evidence. (23, 65, 106, 119, 126, 127, 128, 129, 130, 131, 132, 133)

Bearing in mind that adolescence lasts until around 19.5 years for women and 20.9 years for men,(9, 37) a recent study of first semester Air Force Academy cadets appears to isolate the effect of delayed start times on adolescent academic performance. (35) The researchers, economists from the University of California and the U.S. Air Force Academy, controlled for potentially confounding factors — grading structure, class selection and U.S. Air Force handout photo of two F-22 stealth fightersteachers, for example — to determine the “causal effect” of start times on adolescent academic achievement. (35) The five-year study found that students attending classes prior to 8 a.m. performed significantly worse in all courses taken that day. (35)

“Our findings have important implications for education policy; administrators aiming to improve student achievement should consider the potential benefits of delaying school start time. A later start time of 50 minutes in our sample has the equivalent benefit as raising teacher quality by roughly one standard deviation. Hence, later start times may be a cost-effective way to improve student outcomes for adolescents.” (35) 

Considering this study, Finley Edwards’ seven-year middle school study, (127, 128) the biological evidence, data reflecting the prevalence of sleep deprivation (8, 129) and poor academic performance among adolescents attending early starting schools, (134) economists from the University of Michigan and Columbia University “conservatively” estimate that delaying middle and high school start times “from roughly 8 a.m. to 9 a.m.” will increase student achievement by 0.175 standard deviations on average, with effects for disadvantaged students roughly twice as large as advantaged students, increasing individual student future earnings by approximately $17,500 in present value, at little or no cost to schools; i.e., a 9 to 1 benefits to costs ratio. (135)

Scientists in Kentucky (40) and Virginia (75) found significantly decreased frequencies of automobile crashes among teens in districts where start times were pushed back an hour or more to 8:30 a.m., or later—a significant finding when one considers automobile accidents account for more than one third of all teen fatalities. (140, 141

In reviewing the evidence, on August 1, 2014, scientists from Harvard and Oxford observed, “Studies of later start times have consistently reported benefits to adolescent sleep, health and learning using a wide variety of methodological approaches. In contrast there are no studies showing that early starts have any positive impact on sleep, health or learning.” (17Shortly thereafter, the American Academy of Pediatrics issued a Policy Statement recommending delaying middle and high school classes until 8:30 a.m. or later. (142

Careful planning is required in order to successfully delay start times. (143) Adults may be inconvenienced for the benefit of students. (143, 144) Budgets, busing, and politics determine school schedules more often than students’ best interests. (145, 147) Stakeholders often contend delaying school schedules will disrupt sports, jobs, extracurricular activities, daycare plans, teachers’ personal lives, etc. (131, 145, 148, 149, 150, 151, 152To those objecting to later school scheduling, Mark Mahowald, M.D., former Professor of Neurology at the University of Minnesota Medical School and former Director of the Minnesota Regional Sleep Disorders Center, offers the following response:

“Not a single excuse we’ve heard relates to education. None of the excuses have the word ‘education’ in them. We should send kids to high school in a condition that promotes learning rather than interfering with it.” (153)

early a.m. bus pick up

Endnotes† (additional and new studies, articles, etc., available here)

1. Carskadon, When Worlds Collide: Adolescent Need for Sleep Versus Societal Demands (Jan. 1999) 80 Phi Delta Kappan 5, pp. 348-353, The National Sleep Foundation has recently revised its sleep duration recommendations. (Hirshkowitz, Whiton, Albert, Alessi, Bruni, DonCarlos, Hazen, Herman, Katz, Kheirandish-Gozal, Neubauer, O’Donnell, Ohayon, Peever, Rawding, Sachdeva, Setters, Vitiello, Ware, & Hillard, National Sleep Foundation’s sleep time duration recommendations: methodology and results summary (Mar. 2015) 1 Sleep Health 1, pp. 40-43,

2. (2011 Sleep in America Poll: Communications Technology in the Bedroom (Mar. 2011) Nat. Sleep Foundation, [7 percent of 13 to 18-year-olds report getting less than 6 hours of sleep; 54 percent wake up between 5 a.m. and 6:30 a.m. during the week].)

3. (Eaton, McKnight-Eily, Lowry, Croft, Presley-Cantrell, & Perry, Prevalence of Insufficient, Borderline, and Optimal Hours of Sleep Among High School Students – United States, 2007 (2010) J. Adolescent Health, pp. 1-3,

4. (Knutson & Lauderdale, Sociodemographic and behavioral predictors of bed time and wake time among U.S. adolescents aged 15–17 years (Mar. 2009) 154 J. Pediatrics 3, pp. 426–430,

5. (Working Group on Problem Sleepiness (Aug. 1997) Nat. Center on Sleep Disorders Research, Nat. Inst. of Health,

6. (Noland, Price, Dake, & Telljohann, Adolescents’ Sleep Behaviors and Perceptions of Sleep (2009) 79 J. School Health 5, pp. 224-230,

7. (Interview with Mary Carskadon (2002) Frontline: Inside the Teenage Brain,

8. (Hansen, Janssen, Schiff, Zee, & Dubocovich, The Impact of School Daily Schedule on Adolescent Sleep (Jun. 2005) 115 Pediatrics 6, pp. 1555-1561,

9. (Hagenauer, Perryman, Lee, & Carskadon, Adolescent Changes in the Homeostatic and Circadian Regulation of Sleep (Jun. 2009) 31 Developmental Neuroscience 4, pp. 276-284, “For policy makers, teachers and parents, these results provide a clear mandate. The effects of sleep deprivation on grades, car accident risk, and mood are indisputable. A number of school districts have moved middle and high school start times later with the goal of decreasing teenage sleep deprivation. We support this approach, as results indicate that later school start times lead to decreased truancy and drop-out rates.” (Id., p. 282.)

10. (Millman, edit., Excessive Sleepiness in Adolescents and Young Adults: Causes, Consequences, and Treatment Strategies (Jun. 2005) 115 Pediatrics 6, pp. 1774-1786,

11. (Willis, How Students’ Sleepy Brains Fail Them (Sum. 2009) Kappa Delta Pi Rec., pp. 158-162,

12. (Calamaro, Mason, & Ratcliffe, Adolescents Living the 24/7 Lifestyle: Effects of Caffeine and Technology on Sleep Duration and Daytime Functioning (Jun. 2009) 123 Pediatrics 6, pp. e1005-e1010,;; see also, Rideout, Foehr, & Roberts, Generation M2: Media in the Lives of 8- to 18-Year-Olds (Jan. 2010) Kaiser Foundation,; Am. Academy Sleep Med. (May 14, 2008) Excessive Mobile Phone Use Affects Sleep in Teens,;  Strasburger, School Daze: Why are Teachers and Schools Missing the Boat on Media? (Jun. 2012) 59 Pediatric Clinics N. Am. 3, 705-712,

13. (Graham, edit., Sleep Needs, Patterns and Difficulties of Adolescents: Summary of a Workshop (Nat. Academies Press 2000) p. 18,

14. (Dornbusch, Sleep and Adolescence: A Social Psychologist’s Perspective, publish. in, Adolescent Sleep Patterns, Biological, Social, and Psychological Influences (Carskadon, edit., Cambridge Univ. Press 2002) pp. 1-3,

15. (O’Malley & O’Malley, School Start Time and Its Impact on Learning and Behavior, publish. in, Sleep and Psychiatric Disorders in Children and Adolescents (Ivanenko edit., Informa Healthcare 2008) pp. 79-94,, or

16. (2011 YRBS Data User’s Guide (Jun. 2012) Centers for Disease Control & Prevention,

17. (Kelley, Lockley, Foster, & Kelley, Synchronizing education to adolescent biology: ‘let teens sleep, start school later’ (Aug. 1, 2014) Learning, Media and Technology, pp. 1-17,

21. (Wolfson, Adolescent Sleep Update: Narrowing the Gap between Research and Practice (Mar./Apr. 2007) Sleep Review: The Journal for Sleep Specialists,

22. (Roberts, Roberts, & Duong, Sleepless in adolescence: Prospective data on sleep deprivation, health and functioning (2009) 32 J. Adolescence, pp. 1045-1057,

23. (Wolfson, Spaulding, Dandrow, & Baroni, Middle School Start Times: The Importance of a Good Night’s Sleep for Young Adolescents (Aug. 15, 2007) 5 Behavioral Sleep Med. 3, pp. 194-209,; see also, Fredriksen, Rhodes, Reddy, & Way, Sleepless in Chicago: Tracking the Effects of Adolescent Sleep Loss During the Middle School Years (Jan./Feb. 2004) 75 Child Development 1, pp. 84–95,

25. (Teens and Sleep Poll a Wake-Up Call, Pediatric Sleep Experts Say (Mar. 2006) Brown Univ.,

26. (Sleep In America Poll: Summary of Findings (2006) Nat. Sleep Foundation,

27. (Carskadon & Acebo, Regulation of Sleepiness in Adolescents: Update, Insights, and Speculation (2002) 25 Sleep 6, pp. 606-614,

28. (School and Staffing Survey, Public School Start Time 2011-2012, Nat. Center for Education Statistics,; see also, Harpaz, Starting School Later May Help Sleepy Teens (Jul. 25, 2013) Assoc. Press,

31. (Later Start Times for High School Students (Jun. 2002) Univ. Minn.,

35. (Carrell, Maghakian, & West, A’s from Zzzz’s? The Causal Effect of School Start Time on the Academic Performance of Adolescents (Aug. 2011) 3 Am. Economic J.: Economic Policy 3, pp. 62-81,

36. (Carskadon & Acebo, Regulation of Sleepiness in Adolescents: Update, Insights, and Speculation (2002) 25 Sleep 6, pp. 606-614,

37. (Kruszelnicki, Teenage Sleep (May 3, 2007) ABC Science,

38. (Backgrounder: Later School Start Times (2011) Nat. Sleep Foundation,

39. (Emsellem & Whiteley, Snooze… or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits (Joseph Hill Press 2006) pp. 11-22,

40. (Danner & Phillips, Adolescent Sleep, School Start Times, and Teen Motor Vehicle Crashes (Dec. 2008) 4 J. Clin. Sleep Med. 6, pp. 533–535,

45. (School Start Time and Sleep (2010) St. John’s Med. Center,

46. (Cortez de Sousa, Mazzilli, Louzada, & Macêdo de Azevedo, Sleep-Wake Cycle Irregularity and Daytime Sleepiness in Adolescents on Schooldays and on Vacation Days (Feb./Mar. 2007) 2 Sleep Science 1, pp. 30-35,

47. (Carpenter, Sleep deprivation may be undermining teen health (Oct. 2001) 32 Am. Psychological Assn. Monitor 9,

48. (Sadeh, Maturation of Normal Sleep Patterns – Childhood through Adolescence, publish. in., Sleep and Breathing in Children: A Developmental Approach (Loughlin, Carroll, & Marcus, edits., Informa Healthcare 2000),

49. (Graham, edit., supra, Sleep Needs, Patterns and Difficulties of Adolescents: Summary of a Workshop, p. 16,

50. (Bergin & Bergin, Sleep – The EZZZ Intervention (Dec. 2009/Jan. 2010) 67 Educational Leadership 4,

51. (Graham, edit., supra, Sleep Needs, Patterns and Difficulties of Adolescents: Summary of a Workshop, pp. 15,

52. (Fuligini & Hardway, Daily Variation in Adolescents’ Sleep, Activities, and Psychological Well-Being (2005) 16 J. Research on Adolescence 3, 353-378,

53. (Dawson, Sleep and Adolescents (Jan. 2005) Counseling 101, “Lack of sleep is associated with academic and behavior problems, tardiness and absenteeism, reduced alertness, and heightened irritability.” (Id., p. 11; see also, Dawson, Sleep and Sleep Disorders in Children and Adolescents: Information for Parents and Educators (2004) Nat. Assn. School Psychologist Resources,

54. (Graham, supra, Sleep Needs, Patterns and Difficulties of Adolescents: Summary of a Workshop (Nat. Academies Press 2000) pp. 14-16,; see also, Nilsson, Söderström, Karlsson, Lekander, Akerstedt, Lindroth, & Axellson, Less effective executive functioning after one night’s sleep deprivation (2005) 14 J. Sleep Research, 1-6,

55. (Ng, Ng, & Chan, Sleep duration, wake/sleep symptoms, and academic performance in Hong Kong Secondary School Children (Nov. 2009) 13 Sleep Breath. 4, 357-367,

56. (Kopasz, Loessl, Hornyak, Riemann, Nissen, Piosczyk, & Voderholzer, Sleep and memory in healthy children and adolescents – a critical review (Jun. 2010) 14 Sleep Med. Rev. 3, 167-177,; Sleep, Learning, and Memory (Dec. 2007) Harvard Medical School, Div. Sleep Med.,

57. (Wilhelm, Diekelmann, & Born, Sleep in children improves memory performance on declarative but not procedural tasks (2008) 15 Learning & Memory, 373-377,

58. (Curcio, Ferrara, & De Gennaro, Sleep loss, learning capacity and academic performance (Oct. 2006) 10 Sleep Med. Rev. 5, 323-337,

59. (Taras, Potts-Datema, Sleep and student performance at school (Sept. 2005) 75 J. Sch. Health 7, 248-254,

60. (Emsellem & Whiteley, supra, Snooze… or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits, pp. 63-76,

64. (Pasch, Laska, Lytle, & Moe, Adolescent Sleep, Risk Behaviors, and Depressive Symptoms: Are They Linked? (Mar. 2010) 34 Am. J. Health Behavior 2, pp. 237-248,

65. (Chorney, Detweiler, Morris, & Kuhn, The Interplay of Sleep Disturbance, Anxiety, and Depression in Children (May 2008) 33 J. Pediatric Psychology 4, pp. 339-348,

66. (Liu, Sleep and Adolescent Suicidal Behavior (2004) 27 Sleep 7, pp. 1351-1358,

67. (Gangwisch, Babiss, Malaspina, Turner, Zammit, & Posner, Earlier Parental Set Bedtimes as a Protective Factor Against Depression and Suicidal Ideation (Jan. 1, 2010) 33 Sleep 1, pp. 97-106,; see also, Late-night teens ‘face greater depression risk’ (Jan. 2, 2010) BBC News,

68. (Hale, Bedtimes and the Blues: Evidence in Support of Improving Adolescent Sleep (Jan. 1, 2010) 33 Sleep 1, 17-18,; see also, Emsellem & Whiteley, supra, Snooze… or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits, pp. 190-191,

69. (Goldstein, Bridge, & Brent, Sleep disturbance preceding completed suicide in adolescents (Feb. 2008) 76 J. Consulting & Clinical Psychology 1, pp. 84-91,; see also, Hutchison, Dimensions of Human Behavior: The changing life course (Sage Publications, 3rd ed. 2008) p. 236.)

70. (Liu & Buysse, Sleep and youth suicidal behavior: a neglected field (May 2006) 19 Current Opn. Psychiatry 3, pp. 288-293,

71. (Insufficient sleep among high school students associated with a variety of health-risk behaviors (Sept. 26, 2011) CDC Online Newsroom,

72. McKnight-Eily, Eaton, Lowry, Croft, Presley-Cantrell, & Perry, Relationships between hours of sleep and health-risk behaviors in US adolescent students (Aug. 5, 2011) Preventive Med.,

75. (Vorona, Szklo-Coxe, Wu, Dubik, Zhao, & Ware, Dissimilar Teen Crash Rates in Two Neighboring Southeastern Virginia Cities with Different High School Start Times (Apr. 2011) 7 J. Clin. Sleep Med. 2, pp. 145-151, 

76. (Walker & Stickgold, It’s Practice, with Sleep, that Makes Perfect: Implications of Sleep-Dependent Learning and Plasticity for Skill Performance (2005) 24 Clin. Sports Med., pp. 301-317,

77. (Lack Of Sleep Can Affect Athletic Performance In Teens (May 11, 2005) Science Daily,

78. (Roenneberg, Allebrandt, Merrow, & Vetter, in press, Social Jetlag and Obesity (May 22, 2012) Current Biology 22, pp. 1-5,

79. (Beebe, Lewin, Zeller, McCabe, MacLeod, Daniels, & Amin, Sleep in Overweight Adolescents: Shorter Sleep, Poorer Sleep Quality, Sleepiness, and Sleep-Disordered Breathing (Feb. 8, 2006) 32 J. Pediatric Psychology 1, pp. 69-79,

80. (Liu, Forbes, Ryan, Rofey, Hannon, & Dahl, Rapid Eye Movement Sleep in Relation to Overweight in Children and Adolescents (2008) 65 Archives of General Psychiatry 8, pp. 924-932,; see also, Expert Sources & Comm., Sleep – High Quality and Enough of It – Is Essential for Child Health (Jun. 10, 2010) Brown Univ.,

85. (Less is More: Study Shows that Teens Who Sleep Less Eat More Fatty Foods and Snacks (Aug. 23, 2010) Am. Academy Sleep Med.,

86. (Weiss, Xu, Storfer-Isser, Thomas, Ievers-Landis, & Redline, The Association of Sleep Duration with Adolescents’ Fat and Carbohydrate Consumption (Sept. 2010) 33 Sleep 9,

90. (Clinkinbeard, Simi, Evans, & Anderson, Sleep and Delinquency: Does the Amount of Sleep Matter? (Jul. 2011) J. Youth & Adolescence,

91. (O’Brien & Mindell, Sleep and Risk-Taking Behavior in Adolescents (2005) 3 Behavioral Sleep Med. 3, 113-133, “Risk-taking refers to those behaviors that increase the risk of morbidity and/or mortality.” (Id., p. 115, citation omitted.)

92. (Mednick, Christakis & Fowler, The Spread of Sleep Loss Influences Drug Use in Adolescent Social Networks (Mar. 2010) 5 Plos One 3, e9775,;jsessionid=53330859090783EBB3298D26A4DF42A5.ambra02.)

95. (Moore, Kirchner, Drotar, Johnson, Rosen, Ancoli-Israel, & Redline (Jun. 2009) Relationships Among Sleepiness, Sleep Time, and Psychological Functioning in Adolescents, J. Pediatric Psychology, pp. 1-9,

96. (Emsellem & Whiteley, supra, Snooze… or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits, pp. 25-26,

97. (Glozier, Martiniuk, Patton, Ivers, Li, Hickie, Senserrick, Woodward, Norton, & Stevenson, Short Sleep Duration in Prevalent and Persistent Psychological Distress in Young Adults: The DRIVE Study (2010) 33 Sleep 9, pp. 1139-1145,

100. (Javaheri, Storfer-Isser, Rosen, & Redline, Sleep Quality and Elevated Blood Pressure in Adolescents (Aug. 2008) 118 Circulation, J. Am. Heart Assn., 1034-1040,

105. (Gibson, Powles, Thabane, O’Brien, Molnar, Trajanovic, Ogilvie, Shapiro, Yan, & Chilcott-Tanser, “Sleepiness” is serious in adolescence: Two surveys of 3235 Canadian students (May 2006) 6 Bio Med Central Pub. Health 116,

106. (Bronson, Snooze or Lose (Oct. 7, 2007) N.Y. Mag., web p. 2,

107. (Shatkin, The Parent Letter (Jan. 2007) 5 N.Y. Univ. Child Study Center 5,

108. (Wheaton, Ferro, & Croft, School Start Times for Middle School and High School Students — United States, 2011–12 School Year (Aug. 7, 2015) Centers for Disease Control and Prevention (CDC), 64 Morbidity & Mortality Weekly Rep. 30, pp. 809-813,; see also, Press Release, Most US middle and high schools start the school day too early (Aug. 6, 2015) CDC,, see also, [CDC Infograph].)

109. (Children, Youth, & Families Office, Later School Start Times Promote Adolescent Well-Being (2014) Am. Psychological Association,

110. (Problem Sleepiness (Sept. 1997) Nat. Inst. Health, No. 97-4071,

111. (Educating Youth About Sleep and Drowsy Driving (Sept. 1998) Nat. Inst. Health,

112. (Am. Lung Assoc. of New England, School Daze: A Wake Up Call (Sept. 2008) Healthy Air Matters, p. 4,, “The onset of puberty has been shown to be associated with a phase delay with later sleep onset and wake times. Lifestyle and social factors often mean a chronic sleep debt accumulates during the week, which the teenager attempts to address by sleeping in on weekends, which is ineffective and further contributes to the circadian disruption. Interestingly, the delay of school start time by half an hour from 8:00 to 8:30 A.M. results in a significant increase in sleep duration, with concomitant improvements in alertness, motivation, and mood in adolescents [¶] For adolescents, we suggest that school start times be delayed to align with the physiological circadian propensity of this age group.” (Mukherjee, Patel, Kales, Ayas, Strohl, Gozal, & Malhotra, An Official American Thoracic Society Statement: The Importance of Healthy Sleep. Recommendations and Future Priorities (Jun. 15, 2015) 191 Am. J. Respiratory & Critical Care Med. 12, pp. 1452, 1453, citations omitted,

113. (Park, Falling Asleep in Class? Blame Biology (Dec. 15, 2008) CNN,

114. (Diconsiglio, let me sleep! (Feb. 11, 2002) 134 N.Y. Times Upfront 9, pp. 14-17 [an error in Mr. Diconsiglio’s article is discussed in n. 578, main text].)

115. (Emsellem & Whiteley, supra, Snooze… or Lose!: 10 “No-War” Ways to Improve Your Teen’s Sleep Habits, p. 213,

116. (Gardner, Later Start Times May Foster Better Students (Jul. 5, 2010) U.S. News & World Rep.,

117. (Minn. Med. Assn. Letter to Superintendent Dragseth (Apr. 4, 1994) Edina Pub. Schools,

118. (Wahlstrom, Changing Times: Findings From the First Longitudinal Study of Later High School StartTimes (Dec. 2002) 86 Nat. Assn. Secondary School Principals Bull. 633, pp. 3-21, also, Wahlstrom, Dretzke, Gordon, Peterson, Edwards, & Gdula, Examining the Impact of Later School Start Times on the Health and Academic Performance of High School Students: A Multi-Site Study (Feb. 2014) CAREI, Univ. Minn., pp. 1-72,

119. (Comer, Owens ’80 advocates later start for more sleep (Sept. 27, 2010) Brown Daily Herald,

120. (Owens, Belon, & Moss, Impact of Delaying School Start Time on Adolescent Sleep, Mood, and Behavior (Jul. 2010) 164 Archives of Pediatrics &Adolescence Med. 7, 608-614,; see also, Boergers, Gable, & Owens, Later School Start Time Is Associated with Improved Sleep and Daytime Functioning in Adolescents (Jan. 2014) 35 J. Developmental & Behavioral Pediatrics 1, pp. 11-17,,

125. (Lamberg, High Schools Find Later Start Time Helps Students’ Health and Performance (2009) 301 J. Am. Med. Assn. 21, pp. 2200-2201,

126. (Lufi, Tzischinsky, & Hadar, Delaying School Starting Time by One Hour: Some Effects on Attention Levels in Adolescents (Apr. 2011) 7 J. Clin. Sleep Med 2, pp. 137-143,

127. (Edwards, Do Schools Begin Too Early? (Summer 2012) 12 Education Next 3,

128. (Edwards, Early to Rise? The Effect of Daily Start Times on Academic Performance (Dec. 2012) 31 Economics of Education Rev. 6, pp. 970-983,

129. (Wolfson & Carskadon, Understanding adolescents’ sleep patterns and school performance: A critical appraisal (2003) 7 Sleep Med. Rev. 6, pp. 491-506,

130. (Wolfson & Carskadon, Sleep Schedules and Daytime Functioning in Adolescents (Aug. 1998) 69 Child Development 4, pp. 875-887,

131. (Bronson & Merryman, Nurture Shock: New Thinking About Children (Twelve Books 2009),

132. (Kalish, Early Bird Gets the Bad Grade (Jan. 14, 2008) N.Y. Times,

133. (School Start Time Study (1998) Center for Applied Research and Educational Improvement (CAREI), Univ. Minn.,

134. (Jacob & Rockoff, Organizing Schools to Improve Student Achievement: Start Times, Grade Configurations, and Teacher Assignments (Sept. 2011) Hamilton Project, Brookings Inst., [full paper], [links to abstract, policy brief, and full paper]; see also, Buckhalt, Insufficient Sleep and the Socioeconomic Achievement Gap (Mar. 2011) 5 Child Development Perspectives 1, pp. 59-65,

140. (CDC Nat. Vital Statistics System, Mortality Tables,

141. (Injury Prevention & Control: Motor Vehicle Safety, Teen Drivers: Fact Sheet, Centers for Disease Control & Prevention, “Given the danger posed to young people from car accidents this is a strong reason in itself to change school start times.” (Cline, Do Later School Start Times Really Help High School Students? (Feb. 27, 2011) Psychology Today,

142. (Adolescent Sleep Working Group, Committee on Adolescence, & Council on School Health, School Start Times for Adolescents (Aug. 25, 2014) Pediatrics, pp. 642-649,

143. (Kirby, Maggi, & D’Angiulli, School Start Times and the Sleep–Wake Cycle of Adolescents: A Review and Critical Evaluation of Available Evidence (Mar. 2011) 40 Educational Researcher 2, pp. 56-61,

144. (Riddile, Time Shift: Is your school jet-lagged? (Mar. 14, 2011) Nat. Assn. Secondary School Principals, The Principal Difference,

145. (Wolfson & Carskadon, A Survey of Factors Influencing High School Start Times (Mar. 2005) 89 Nat. Assn. of Secondary School Principals Bull. 642, pp. 47-66,

147. (Wahlstrom, The Prickly Politics of School Starting Times (Jan. 1999) 80 Phi Delta Kappan 5, pp. 344-347,

148. (Fernandez, Politician Hopes to Reawaken Sleep Legislation (Mar. 25, 1999),

149. (Eight Major Obstacles to Changing School Start Times (2011) Nat. Sleep Foundation,

150. (Worried About Keeping Extra-curriculars, W.A.K.E.,

151. (FCPS Do Not Push School Start Times Back (2009) Fairfax Underground,,

152. (Shaddox, Delaying School Start Times Causes Alarm (Oct. 25, 2010) Miller-McCune,

153. (Delisio, It’s About Time (and Sleep): Making the Case for Starting School Later (Jun. 3, 2003) Education World,

Books cited:

Bronson & Merryman, Nurture Shock: New Thinking About Children (Twelve Books 2009)

MindellOwens, Clinical Guide to Pediatric Sleep: Diagnosis and Management of Sleep Problems (Lippincott Williams & Wilkins, 2nd ed. 2010)

Coch, Fischer, & Dawson, Human Behavior, Learning, and the Developing Brain: Typical Development (Informa Healthcare 2010)

Sleep and Breathing in Children: A Developmental Approach (Loughlin, Carroll, & Marcus, edits., Informa Healthcare 2000)

†     Gaps in the endnote numerical sequence exist to allow this summary to readily accommodate new studies and articles. These endnotes do not necessarily correspond numerically with those in the main text.

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