Over the past 15 years, abundant scientific evidence has accumulated that shows America's schoolchildren are chronically sleep deprived, and it is affecting their learning, mood, safety and health.
Furthermore, the general trend is only worsening, with children of all ages receiving, on average, about one hour per night less sleep than their peers a generation ago. Although many factors have contributed to this decline, one pervasive problem that has received significant attention is early school start times.
The National Sleep Foundation makes the following recommendations: School-age children (5 to 10 years) should get 10 to 11 hours of sleep per night; "teens" (10 to 17 years) should get 8.5 to 9.25 hours of sleep per night.
In stark contrast to these recommendations, a 2005 NSF telephone survey of teenagers and their parents showed only 60 percent of ninth-graders got at least eight hours of sleep per night. By the 10th grade, the number had dropped to 30 percent, and it continued to fall. By 12th grade, only 9 percent were getting an optimal amount of sleep as defined by the NSF guidelines.
In 2007, the Centers for Disease Control and Prevention's Youth Risk Behavior Survey, involving 12,154 students nationwide, confirmed those findings reporting that 69 percent of students had insufficient sleep on school nights, with only 7.6 percent reporting optimal hours of sleep. These objective measures are reinforced by the students' self-reports that more than 50 percent feel they don't get enough sleep to "perform at their best."
Still not convinced? Ask any parent of a teen when their adolescent awakens on the weekends and holidays, when they are not constrained by early school start times.
While children of all ages can be affected by inadequate sleep, the situation with older teens is especially acute. As we have seen, student sleep time progressively declines over the high school years as social, athletic and academic demands increase.
This situation is compounded by biological changes in the sleep pattern of adolescents. When it starts to get dark, preadolescents and adults begin to secrete a hormone, melatonin, which makes us sleepy. During puberty, there is a "phase shift" in the circadian rhythm system, our so-called biological clock, which results in the release of melatonin being delayed as much as two hours. It is this phase shift, at least in part, that accounts for the widely observed tendency of teens to prefer to stay up late and sleep in in the morning.
Thus, even if we can get our teenagers to bed at a decent time, they end up tossing and turning because, biologically, they aren't meant to be sleepy yet. Conversely, when those early morning alarms are going off, our adolescents' melatonin level is still high and encouraging a return to sleep at the very time we are nagging them to get out the door or, in first and second period, when they are struggling to stay awake in class.
This chronic sleep deprivation is not without consequences. Sleep restriction in children has been linked to daytime sleepiness, inattention, poor motivation, memory problems, increased irritability, decreased socialization, low self-esteem, increased anxiety and depression, and suicidal behaviors.
Many of the prototypical traits of modern adolescence could just as easily be attributed to sleep deprivation as to raging hormones. Not surprisingly, there is further evidence (though limited) that these sleep deprivation problems with attention, memory consolidation, motivation, etc., contribute to overall lower grades and standardized test scores.
Finally, physical problems have been linked to chronic sleep restriction including: increased auto accidents, impaired immune function and obesity.
In 1997, seven high schools in the Minneapolis Public School District shifted their school start times from 7:15 a.m. to 8:40 a.m. In the two years following this change, data showed improved attendance, fewer depressive symptoms, less daytime sleepiness, increased student calmness in the cafeteria and hallways, fewer school counselor and nurse visits, and fewer disciplinary referrals.
Parents described their children as being "easier to live with" and that they were having more actual conversations with their children in the morning.
A recent study in an independent boarding school in southern New England, based on a more modest change of only 30 minutes, demonstrated a decrease in daytime sleepiness, fewer and less severe depressive symptoms, decreased feelings of annoyance, a 56 percent decline in requests for "rest passes" and a 45 percent decrease in first class absences/tardiness.
Despite the original intentions of the school administration to return to the 8 a.m. start after the conclusion of the experiment, "students and faculty overwhelmingly voted to retain the 8:30 a.m. start."
One faculty member described the change as "the single most positive impact to my general quality of life at [the school] since I started 12 years ago."
A large public school system in Lexington, Ky., delayed start times one hour. Despite rapid population growth in the study county, the average crash rates for drivers aged 17 or 18 in the two years after the change decreased 16.5 percent, whereas there was a significant increase of 7.8 percent across the same time period in the rest of the state.
For a school district to adapt a schedule that has existed unchanged for as long as anyone can remember is obviously a huge undertaking.
Nevertheless, the research studies demonstrate significant, consistent, positive results for those that do. In an age in which there has been so much attention focused on school reform, the failure of this issue to receive significant, nationwide attention is disappointing.
So, the next time your local school board convenes, go to the meeting and suggest the formation of an exploratory committee -- then let the conversations begin. Healthier, happier, safer and better-educated children just might be the result.
John Norris is a pediatrician with the West Penn-Allegheny Health System. He is also the parent of a high schooler who must be at the bus stop at 7:10 a.m.