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Is Starting School Later Better for Teen Health? It’s Complicated

California schools are starting later to let students sleep in. Will it pay off?



This year, most high schools and middle schools in California cannot begin before 8:30 a.m. and 8 a.m., respectively, thanks to a new law.

The American Academy of Pediatrics (AAP) has declared a national “epidemic” of adolescent sleep deprivation, and this law, the first in the country to set statewide mandates for school start times, is a major step toward combating that problem. The American Academy of Pediatrics (AAP) and the U.S. Centers for Disease Control and Prevention (CDC) have both argued for years that middle and high school bell times shouldn’t begin before 8:30 a.m.

Teen sleep deprivation is a serious issue in the United States, and delayed school start times are one solution. CDC statistics show that only about one-third of high school students are getting the full eight hours of sleep per night that they need on school nights. Lack of sleep has been linked to a variety of negative outcomes in young adults, including but not limited to: overweight and obesity, substance abuse, depression, and poor school performance.

Circadian rhythms, which are influenced by light and serve as internal cues to regulate sleep, have been shown to evolve over the course of a person’s lifetime. That’s why it’s not unusual for mature people to find themselves waking up earlier on their own accord. The circadian rhythms of teenagers are not compatible with school schedules that begin before 8 a.m., as they function best when they go to bed around 11 p.m. or midnight and wake up around nine hours later.

Further Reading: Circadian Clocks May Be the Next Step in Personalized Medicine.

It is a relic of a time when most families did not have two working parents and, consequently, did not have to worry about keeping a 9-to-5 schedule that early school start times are still the norm. Bus routes, class times, sports practices, and other activities all need to be scheduled, so students have been waking up early.

However, there is no scientific basis for these timetables. Research has long suggested that adolescents are doomed to fail because of the discrepancy between their internal clocks and the demands of the outside world. After starting school an hour earlier than usual, a small group of students reported “significant sleep deprivation and daytime sleepiness,” according to a study published in 1998.

Evidence suggests that the opposite is true when start times are pushed back. Five years after seven Minneapolis public high schools moved their start times from 7:15 a.m. to 8:40 a.m., a study found that the change resulted in students getting an extra hour of sleep per night, improved school attendance, and reduced student depression. After a high school in Rhode Island shifted its start time from 8 to 8:30 in the morning in 2010, researchers found that students benefited from an extra 45 minutes of sleep per night, felt less tired, and had better attitudes.

After the Denver school district pushed back morning start times by 40 to 70 minutes, students in middle and high school were much more likely to get the recommended amount of sleep each day (2021 study). Students in Colorado who began the school day before 8:30 a.m. were found to have a non-significantly higher rate of suicide attempts compared to their later-starting peers. Although more study is needed, and numerous confounding variables may obscure the link, the findings suggest that starting classes later may improve adolescents’ mental health.

However, rearranging bell schedules isn’t a magic bullet. Some schools reported positive effects, while others reported negative or unclear consequences, according to a review of research on the correlation between later start times and academic achievement published in February 2022.

As if that weren’t enough, there are a plethora of practical considerations. When 2016 rolled around, public schools in Durham, North Carolina, shifted their start times from 7:30 to 9 a.m. Only 26% of teachers and staff members said students were better rested the following year, and only 14% said they were learning more. As few as 13 percent of teachers and 27 percent of parents supported keeping the new schedule. Why? There was a significant change in the length of the school day, which meant that extracurricular activities, after-school jobs, and homework would take place later in the day, keeping some children up past their usual bedtimes.

For more, click here: An Inside Look at the Huge Effort to Reform Reading Instruction for Children

After a two-year experiment with later bells caused numerous logistical headaches, such as inability to coordinate with neighboring schools and scheduling extracurriculars, Newport, Rhode Island schools reverted back to their original start times in 2018. Some schools have discovered, after shifting their schedules later, that transportation can be a problem, whether it’s rearranging bus schedules, dealing with traffic patterns, or finding ways for working parents to drop off kids later in the morning.

In a January Cal Matters op-ed, California educator Jeremy Adams voiced many of these same concerns and noted that the new state law will create hardships for teachers who must remain on campus for extracurriculars that begin after the school day ends. Adams predicted that the law would lead to a “unintended consequences” study.

There is still much investigation happening in the school opening time debate. For instance, in Colorado, researchers are looking at how moving school start times impacts the well-being of everyone involved, not just students. According to Deborah Temkin, an expert in the field of education, all eyes will be on the statewide shift in California after the policy was first passed in 2019. Temkin speculated that other states would follow suit if the experiment proved successful with few unintended consequences.

It’s too soon to tell how the experiment will go since the new school year has just begun. Nonetheless, as some California high school students told the Mercury News, it will take more than a later starting bell to cure their exhaustion. “No matter what time you wake up in high school, you’re going to be tired,” said senior Anika Bose. I can finally get a cup of coffee before class.