Teens’ Sleep Rhythms And School Start Times: “A Perfect Storm”
Sleep is critical to brain development, memory function, and cognitive skills, especially among children and teenagers, notes Gina Cairney in Education Week. But many teenagers are not getting enough sleep, in part because the early start times of many high schools are in conflict with their biological rhythms, which during adolescence prompt them to stay up later and sleep later. Cairney reports on a symposium held in in Rockville, MD, last week, which explored the potential benefits of changing school start times:
“Sleep deprivation is considered a widespread, chronic health problem among adolescents, according to the Arlington, Va.-based National Sleep Foundation, and can have negative effects on their cognitive development and cause mental and emotional problems. Experts recommend that high-school-age youths get around nine hours of sleep per night, but the reality is that many teenagers get seven hours or less, according to the sleep foundation.
Sleep changes in adolescents is ‘kind of a perfect-storm scenario,’ said Dr. Judith Owens, the director of sleep medicine at Children’s National Medical Center in Washington, with many factors ‘basically conspiring to increase the risks of insufficient sleep in this population.’ As adolescents hit puberty, their natural sleep-wake cycles begin to shift such that they are unable to fall asleep as early as they did when they were in elementary school. Hence, it’s normal for teenagers to be awake until about 11 p.m., according to Dr. Owens.
But with some schools starting as early as 7 a.m., this means many teenagers aren’t getting the recommended nine hours of sleep for proper rest and development. This sleep loss can be further exacerbated by environmental factors like light exposure from computer screens or mobile phones, which can distract the brain from thinking it’s time to sleep. As more research becomes available on the relationship between adolescent sleep and school start times, educators, parents, and students throughout the country are taking steps to bring school start times into the spotlight.
A study published in May 2012 by Education Next looked at more than 146,000 middle schoolers in the Wake County, N.C., public school system and found that pushing back their start times an hour increased standardized math and reading scores by 2 percentile points to 3 percentile points. Although the sample is small, the study’s main author, economist Finley Edwards from Colby College in Waterville, Maine, said the findings are significant enough to be important, suggesting that later start times can be a relevant policy change for those districts trying to find ways to improve students’ academic achievement.” (Read more here.)
Whenever the subject of later school start times is broached, I hear objections about the problems this would cause for after-school activities, sports, etc. But shouldn’t students’ health, first of all, and academic performance, second of all, be our primary concerns?
The experiment with the start times only tells you that the experimental group had a small benefit over the timescale of the experiment. It does not say that if this became the norm, that standards would rise.
The best explanation I have heard is that adolescent brains move to a circadian rhythm of more than 24 hrs (hence the late nights. However, this means that, if you change the start of day by 1hr, within a few weeks they will be demanding another hour.
Circadian rhythms are reset each day by darkness as night and blue light in the morning. Rules about ‘no screens after 11pm’ are helpful in re-establishing the 24hr rhythm.