UMN study: Later school start times better for adolescent development

Many high schools across the country are debating if later start times are better for students.  A recent University of Minnesota study found that later opening bells were associated with better mental and behavioral health for adolescents.

In 2014, the American Academy of Pediatrics recommended that all high schools start no earlier than 8:30 a.m. This suggestion came off the heels of mounting scientific evidence that early high school start times negatively impact adolescent sleep duration, performance in school and safety.

“Although many school administrators know that early start times can harm students academically, the health consequences of chronic sleep deprivation are not as well known to them,” said Aaron Berger, M.P.H., Ph.D. student at the University of Minnesota School of Public Health, a former high school teacher, and one of the authors on this study. “We wanted to be able to provide schools with data to inform their decisions on school day scheduling,” Berger said.

Berger and UMN School of Public Health assistant professor Rachel Widome, Ph.D., M.H.S., partnered with Kyla Wahlstrom, Ph.D. from the UMN College of Education and Human Development. With funding from the US Centers for Disease Control and Prevention (CDC), Dr. Wahlstrom surveyed over 9,000 students from eight high schools in five districts across the U.S. from 2010-13 on sleep and select health, academic and behavioral issues. The schools in the study had start times ranging from 7:35 am to 8:55 am. Students responding to the Teen Sleep Habits Surveywrote in their usual school-night bedtime and school-day wake-up time. The researchers used that information to calculate students’ average sleep duration on school nights and correlated their sleep-wake times to the students’ survey responses about their substance use and mental health status.

The study found that adolescents attending schools with later start times reported greater sleep duration and later wake-up times.  Greater sleep duration and later wake-up times were also associated with better mental health outcomes.

For each additional hour of sleep reported, there was a 28% reduction in students who said they felt unhappy, sad or depressed. Longer sleep durations were also associated with fewer students reporting use of alcohol, cigarettes and other substances.

“If schools can improve adolescents’ sleep by delaying their start times, and, as a result, enable adolescents to go through high school with better overall mental health and with less substance use, this is not only beneficial to their school experience, but it will set them up for success in their adult lives,” Wahlstrom said. “The findings from this study tell us that the health and well-being of our teens is something school districts need to take into account when setting a start time.”

This paper entitled, “Relationships between school start time, sleep duration, and adolescent behaviors”, was published in June, 2017, in the journal Sleep Health.

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