Abstract
Why Aren’t Adolescents Getting the Sleep They Need?
Adolescents (10-17 years of age) need between 8 and 10 h of sleep each night. Yet surveys show that nearly 90% do not get the recommended amount of sleep on school nights. The problem of insufficient sleep is so widespread that it has led the American Academy of Pediatrics (AAP), the US Centers for Disease Control and Prevention, and other health-related organizations to recognize adolescent sleep deprivation as a major public health concern.
The underlying biological changes occurring during adolescence can help us understand the root of this problem. Two brain systems tell us when to be asleep and when to be awake. First, our brain builds up sleep drive the longer we stay awake; this pressure eases as we sleep. During puberty, sleep pressure builds up more slowly and allows adolescents to stay awake longer before feeling sleepy. Second, a ~24-h biological clock supports alertness during the day and sleep at night. During puberty, the timing of this clock delays, pushing support for staying awake later into the evening and making it hard for students to fall asleep in the early night. Ideally, these 2 brain systems keep us asleep at night and awake during the day, but the challenge for many adolescents is that their alarm clocks on school days disrupt the natural coordination of these brain systems. The biological drive to sleep late and the societal drive to wake up early create a mismatch that prevents students from getting the recommended 8 to 10 h of sleep they need. Worse, waking up too early means their brains are not ready for the school day to begin.
Why Should We Care?
Evidence shows that insufficient sleep in many adolescents is largely due to early school start times. The consequences are alarming, because lack of sleep in teenagers is associated with increased rates of depression and anxiety, suicidal thoughts, substance use and abuse, and delinquent behaviors. In addition, many of the main symptoms of sleep deprivation, such as the inability to concentrate, irritability, and trouble coping with stress, are also typical symptoms of attention-deficit/hyperactivity disorder, which may challenge accurate diagnosis and treatment for students whose behavior mimics such disorders. Sleep-deprived adolescents also have higher rates of car crashes, sports injuries, and obesity. Finally, insufficient sleep significantly impairs the ability to acquire and store knowledge, which has a negative effect on learning and academic performance.
Studies from around the world indicate that later school start times benefit students. In these cases, students can follow their biological timing, go to sleep later in the night, and sleep later in the mornings, resulting in more sleep overall and a better fit of sleep to internal clock time. More sleep and later rising on school days are associated with better grades, attendance, mood, and well-being. The gains from delaying start times are not limited to increased sleep, along with improved mood, behavior, and academics. Studies in the United States also show that teen drivers attending schools with later start times have significantly fewer car accidents. Further, an analysis by the Brookings Institute found that delaying start times by 1 h would lead to a lifetime earnings gain of $17, 500 per student, largely because of the academic gains from better rested students. A large economic analysis by the RAND Corporation in 2017 estimated the economic impact of a nationwide delay of school start times to 0830 h, projecting an economic gain of more than $8.6 billion to the US economy in the first 2 years alone, even after accounting for the costs of moving bus schedules and other changes.
How Do We Fix It?
The AAP recommended a national delay in middle and high school start times to start no earlier than 0830 h. If enacted, this policy would provide an opportunity for students to sleep later in the mornings—more in line with their natural rhythms—which would extend their nightly sleep toward healthy levels. When deciding what start time is appropriate for a specific school district, it is important to consider such factors as geographical region, socioeconomic status, and student transit options. Similarly, the recommendations for school districts whose students use public transportation versus those with longer commuting times versus those whose students rely on personal vehicles may differ. Ideally, the decision to delay the secondary school start time should be informed by these factors as well as advice from sleep and circadian researchers, who can help determine whether teenagers in specific communities are getting adequate and well-timed enough sleep.
Why is Changing Start Times Hard?
There are many costs to delaying start times. Changing bus schedules can be expensive and time-consuming. Delaying start times can also lead to delaying extracurricular activities such as sports practices and club meetings, affecting field and coach availability. For schools that compete across districts, a mismatch in school day end times can make scheduling competitions difficult. In addition, many parents rely on older sibling care for younger children, which can be difficult if older teens are not home until later in the afternoon. These concerns are valid and must be considered on a case-by-case basis to decide the best start time for each school or district. In some cases, schedules can be changed relatively easily with prudent rescheduling of primary school to earlier start times that are more compatible with young students’ internal rhythms. Implementing a somewhat earlier (e.g., ~0800 h) start for primary schools and later (no earlier than 0830 h) start for middle/high schools may require minimal extra investment in school transportation and yet result in schedules more in tune with the biology of both young children and teenagers.
Altering school start times affects many thousands of people—students, parents, teachers, and so forth. We acknowledge the challenges such changes present; however, for adolescents, the benefits of delaying school start times are supported by a preponderance of evidence: students are healthier, safer, and more successful when given the opportunity to sleep later in the mornings. We urge policy makers, school administrators, and communities to follow the recommendations of the AAP and make the challenging but important decisions necessary to tackle this problem and give youngsters an opportunity for healthier sleep.
