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Adolescents benefit from delayed school start time
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Pushing back the start of the school day by a half hour at a private high school significantly improved students’ alertness, mood and health, said researchers from Hasbro Children’s Hospital in Providence, R.I.
“A number of important biologically based changes in sleep regulation occur during adolescence,” the researchers wrote. “Beginning at the onset of puberty, adolescents develop as much as a 2-hour sleep-wake phase delay (later sleep onset and wake times) relative to sleep-wake cycles in middle childhood.” However, adolescents’ need for sleep does not decrease and remains at about 9 hours per night. Yet, schools do not adapt start times to teenagers’ change in circadian rhythm, and this may be responsible, in part, for why most of this population appears sleep-deprived.
To determine whether adolescents would benefit from a later start to the school day, the researchers implemented a 2-month long change during which classes began at 8:30 instead of 8:00 a.m. at a private school that enrolled grades 9 to 12 and had a mix of boarding and day students. The 201 teenagers included in their analysis completed before and after surveys on sleep patterns and behavior, daytime sleepiness and mood. Information on visits to the school’s health center and absences or tardies were also gathered using school records.
Results indicated that, after the new start time, students’ sleep duration on school nights increased by 45 minutes (95% CI, 27-49), and their average reported bedtime on school nights was 18 minutes earlier (95% CI, 7-29). Data also showed a marked decline of 79.4% in the number of students getting less than 7 hours of sleep per night, while the number of students getting at least 8 hours of sleep rose from 16.4% to 54.7%.
Survey responses also pointed to improvements in mood, according to the researchers, with adolescents reporting more motivation to participate in activities and feeling less depressed. Daytime sleepiness was also reduced, and first class absences or tardies decreased by 45%.
“The results of this study add to the growing literature supporting the potential benefits of adjusting school schedules to adolescents’ sleep needs, circadian rhythm, and developmental stage and of optimizing sleep and alertness in the learning environment,” wrote the researchers.
However, Kyla Wahlstrom, PhD, of the University of Minnesota in St. Paul, noted in an accompanying editorial that not many schools are receptive to later start times for a variety of reasons. “The time that a school starts is felt to be sacrosanct by those who have come to rely on it as a predictable part of their day and life,” she wrote. “In a sense, the time that school starts is like a community norm.”
Additionally, other factors, including economics and transportation issues may play a role in the debate, said Wahlstrom, although she believes these problems may be overcome if people are given quality information. “In the end, having comprehensive information and impartial presentation of what is known, and not assumed, is needed to really begin the local dialogue…Our teenagers need and deserve our best informed thinking about all of this; having the facts in hand is the best place to start.”
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