NASHVILLE, Tenn. — High school classes start so early in this town that some kids board the buses at 5:30 in the morning.
Only 10 percent of public schools nationwide start before 7:30 a.m., according to federal statistics. But in Nashville, classes start at 7:05, a fact that new mayor Freddie O’Connell has criticized for years.
“It’s not a badge of honor,” he said when he was still on the city council.
After his election in September, O’Connell announced that delaying school start times was a cornerstone of the education policy he was promoting. He and others around the country try to emphasize that teenagers are not lazy or to blame for getting too little sleep. It’s science.
“All teenagers have this change in their brain that makes them not feel sleepy until about 10:45 or 11 at night,” said Kayla Wahlstrom, a senior research fellow in the University of Minnesota’s College of Education and Human Development. She studies how education policy affects learning and has been a teacher. “It’s a change that’s biologically driven.”
Teen sleep deprivation is linked to mental health problems, poorer grades, traffic accidents, and more. That’s why states, including California and Florida, have mandated later start times. Individual districts across the country — including some in Tennessee — have made the same change.
But opposition to later launches has less to do with science than with logistical and financial difficulties, especially with basics like bus transport.
State Rep. John Ray Clemons, D-Nashville, tried to pass a bill mandating later start times in 2022.
“I’m starting to experience that with one of my own children,” he said during a committee hearing on the bill. He dug into biology, including the famous sleep hormone melatonin.
Melatonin makes people feel sleepy. The brain starts producing it when it gets dark outside, and its production peaks in the middle of the night. Adolescent brains start releasing melatonin about three hours later than the brains of adults and younger children, according to the American Chemical Society. When teenagers wake up early, their brains are still producing melatonin.
“Because of the way adolescent bodies release melatonin, waking up a teenager at 7 a.m. is similar to waking up one of us at 4 a.m.,” Clemons said.
He brought in a local parent, Anna Thorsen, who testified that the later start time legislation could protect vulnerable children like hers.
“My youngest daughter is a freshman who suffers from a rare genetic epilepsy that killed her older sister last year,” she said. “In fact, last March, my youngest daughter had a life-threatening seizure that was partially triggered by sleep deprivation.”
Rep. John Ragan, a Knoxville Republican, said almost all of the feedback he’s heard about the bill has come from Nashville.
“Go to your school board and tell them to change the rules, the law, their start times,” he said. “But yes mandate [the rest of the state] are they doing this because of a school board that won’t listen to their parents?”
Legislative leaders heard the bill once. It did not pass into state law.
That leaves Nashville, a city that often calls itself the Silicon Valley of healthcare, to forge its own path. O’Connell is already on the case. The mayor has some power over the school budget, giving him influence over education policy. However, the school board must determine the start times.
“Starting early, especially for teenagers, is problematic,” the mayor said. “We also know that making a change—even a 30-minute change—requires a lot of logistics.”
A major concern is bus transportation. Even in normal times, districts use the same buses and drivers for students of all ages. They change the start times to do this, with high schoolers arriving and leaving school earlier in the day. The idea is that they can manage alone in the dark at a bus stop more easily than younger children and it also allows them to get home first to help look after younger siblings after school.
If high schools start as late as middle and primary schools, this would likely put a strain on transport resources. O’Connell said Nashville’s limited mass transit compounded the problem.
“This is one of the biggest problems to solve,” he said.
A few years ago, Collierville, a neighborhood in the suburbs of Memphis, started a study on school start times. That district serves far fewer students, 9,000, compared to Nashville’s roughly 86,000.
Collierville officials estimated in the study that bus costs associated with delayed start times could be as high as $1.4 million annually. This estimate suggests that the area will need more drivers, more fuel and maintenance, more storage space and additional support staff – such as an additional dispatcher and mechanic.
However, the district delayed high school start times in 2018.
O’Connell said one of the concerns he’s heard from parents is financial, such as needing help with a family business or needing their students to help generate household income in other jobs , after the school released them.
The National Sleep Foundation, a nonprofit that advocates for later start times, conducted a 2022 survey of parents, teachers and other adults that found only about a third of parents who responded wanted later start. Adults in general and teachers reacted slightly more favorably, but less than 40% of each group supported postponing the day.
A 2022 National Education Association article found that many parents who oppose later start times don’t necessarily question the science; they are concerned about the schedule.
Wahlstrom, the education researcher, said he fears parents are underestimating how important sleep is to brain development and academic achievement, especially on weeknights.
“Sometimes both parents and teenagers think they can just catch up on sleep at the weekend. That’s a completely wrong assumption,” said Wahlstrom, who likened sleep to food for the brain. “It’s like, ‘Okay, we’re going to deprive ourselves of proper food three days of the week, but then we’re going to gorge on food on the weekend.’ That’s not healthy.”
She explained how lack of sleep can hinder success in school: the brain moves memory into long-term storage during deep sleep, so missing that break means retaining less material.
But — perhaps more importantly — sleep helps teens improve their mental health. US Surgeon General Vivek Murthy has raised the alarm about young people’s mental health, noting that a third of teenage boys overall and half of teenage girls report a persistent sense of hopelessness.
And Wahlstrom said sleep deprivation in teens leads to poorer mental and behavioral health, which can affect the whole family. She and her team conducted a Centers for Disease Control and Prevention-funded study on the effects of later start times on students in ninth through 12th grades, surveying 9,000 students at eight high schools in Minnesota, Colorado and Wyoming since 2010 by 2013. They found students who got at least eight hours of sleep were less likely to report symptoms of depression.
“We know there is more drug, cigarette and alcohol use when a teenager gets less than eight hours,” she said. “We also know that there is a significant association between teenage depression and any amount of sleep that is less than eight hours.”
More than 92 percent of parents surveyed in a Minnesota school district as part of her earlier studies said their teen was easier to live with after the later start time went into effect.
“Many parents have told me anecdotally that their child is a different child. They can talk to them at breakfast. They are chatty in the car. They don’t have mood and take-off episodes,” she said. “Parents just say it’s remarkable that this has made such a difference in their child’s life and their family dynamic.”
This article is from a reporting partnership that includes WPLN and KFF Health News.
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