Science says teens need more sleep. So why is it so hard to start school later?
NASHVILLE, TENNESSEE — High school classes begin so early in this city that some students board buses at 5:30 a.m.
According to federal data, only 10% of public schools in the United States begin before 7:30 a.m. In Nashville, however, classes begin at 7:05 a.m., which the city’s new mayor, Freddie O’Connell, has long criticized.
“It’s not a badge of honor,” he said while still on the city council.
Since his election in September, O’Connell has stated that delaying school start times is a key component of the education policy he advocates. He and others across the country have been attempting to emphasize that teenagers are not lazy or to blame for sleeping too little. It’s a fact of science.
“All teenagers have this shift in their brain that causes them to not feel sleepy until about 10:45 or 11 at night,” said Kyla Wahlstrom, a senior research fellow in the College of Education and Human Development at the University of Minnesota. She used to be a teacher and studies how education policy affects learning. “It’s a shift that is biologically determined.”
Sleep deprivation in teenagers has been linked to mental health issues, poor grades, traffic accidents, and other problems. As a result, states such as California and Florida have mandated later start times. Individual districts across the country have made the same change, including some in Tennessee.
However, opposition to later starts stems from logistical and financial difficulties, particularly with basic services such as busing.
Nashville Democrat State Rep. John Ray Clemmons attempted to pass legislation mandating later start times in 2022.
“I’m starting to experience this with one of my own children,” he said during a bill committee hearing. He studied biology, including the well-known sleep hormone melatonin.
Melatonin makes people sleepy. When it gets dark outside, the brain starts producing it, and it peaks in the middle of the night. According to the American Chemical Society, adolescents’ brains begin releasing melatonin about three hours later than adults’ and younger children’s brains. When teenagers wake up early, their brains continue to produce melatonin.
“Because of the way adolescents’ bodies release melatonin, waking a teen at 7 a.m. is akin to waking one of us at 4 a.m.,” Clemmons said in a statement.
Anna Thorsen, a local parent, testified that 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 went on to say. “In fact, last March, my youngest daughter had a life-threatening seizure that was partially induced by sleep deprivation.”
Rep. John Ragan, a Republican from Knoxville, said almost all of the feedback he received on the bill came from Nashville.
“Go to your school board and tell them to change the rule, change the law, change their start times,” he went on to say. “But to mandate [the rest of the state] do this because of one school board that doesn’t want to listen to their parents?”
The bill was given one hearing by legislative leaders. It did not become state law.
That leaves Nashville, often referred to as the Silicon Valley of health care, to forge its own path. O’Connell has taken over the investigation. The mayor has some control over the school budget, giving him some sway over education policy. Start times, however, are determined by the school board.
“Early start times, particularly for adolescents, are problematic,” said the mayor’s office. “We also know that making a change — even a 30-minute change — has a lot of logistics.”
Busing has been a major source of concern. Even when things are normal, districts use the same buses and drivers for students of all ages. To accomplish this, they stagger start times, with high school students arriving and leaving school first. They can handle being alone in the dark at a bus stop better than younger children, and it also allows them to get home first to help care for younger siblings after school.
If high schools started as late as middle and elementary schools, transportation resources would be strained. According to O’Connell, Nashville’s limited mass transit exacerbates the problem.
“That is one of the biggest issues to resolve,” he told reporters.
Collierville, a district in suburban Memphis, began a study on school start times several years ago. That district has 9,000 students, compared to Nashville’s approximately 86,000.
According to the study, busing costs associated with delayed start times could cost Collierville up to $1.4 million per year. This estimate assumed the district would require more drivers, more fuel and maintenance, more storage facilities, and more support personnel, such as a dispatcher and mechanic.
Despite this, the district did move high school start times back in 2018.
One of the concerns O’Connell has heard from parents is financial, such as the need for assistance with family-run businesses or for their students to help generate household income at other jobs after school.
The National Sleep Foundation, a non-profit that advocates for later start times, conducted a survey of parents, teachers, and other adults in 2022 and discovered that only about one-third of the parents polled desired later starts. Adults in general and teachers in particular responded favorably, but less than 40% of each group supported delaying the day.
According to a 2022 National Education Association article, many parents who oppose later start times are concerned about scheduling rather than science.
Wahlstrom, the education researcher, fears that parents underestimate the importance of sleep to brain development and academic performance, particularly on weeknights.
“Parents and teenagers alike may believe that they can catch up on sleep over the weekend. “That is a completely false assumption,” said Wahlstrom, who equated sleep to brain food. “It’s as if they’re saying, ‘OK, we’re going to deprive ourselves of adequate food three days a week, but then we’re going to gorge ourselves on food on the weekend.'” That’s not good.”
She explained how a lack of sleep can impede academic success: “During deep sleep, the brain shifts memory into long-term storage,” so missing out on that rest means retaining less material.
However, and perhaps more importantly, sleep assists teenagers in improving their mental health. Surgeon General Vivek Murthy of the United States has been sounding the alarm about youth mental health, noting that one-third of teenagers overall and half of teenage girls have reported persistent feelings of hopelessness.
And, according to Wahlstrom, teen sleep deprivation leads to poor mental and behavioral health, which can affect the entire family. From 2010 to 2013, she and her colleagues surveyed 9,000 students at eight high schools in Minnesota, Colorado, and Wyoming for a study funded by the Centers for Disease Control and Prevention on the effects of later start times on ninth to 12th graders. They discovered that students who got at least eight hours of sleep were less likely to report depressive symptoms.
“We do know that there is greater use of drugs, cigarettes, and alcohol when a teen is getting less than eight hours,” she went on to say. “We also know that there is a significant link between teenage depression and any sleep amount that is less than eight hours.”
More than 92% of parents polled in a Minnesota school district as part of one of her previous studies said their teen was easier to live with after the later start time was implemented.
“Many parents have told me anecdotally that their child is a different child.” They can communicate with them over breakfast. They talk a lot in the car. “They don’t have mood swings or fly off the handle,” she explained. “The parents are just saying it’s remarkable that this has made such a change in their child’s life and their family dynamics.”
