Lewis, a mother of two, helped spark the first law in the nation requiring healthy school start times for adolescents — a law that will be put into action in California later this summer.
Lewis shared why sleep is so important for teenagers, how much sleep teens should be getting, and why they need to sleep more than adults. She touches on all the factors that can negatively affect teen sleep: technology, gender, sexual identity and socioeconomic status, to name a few.
CNN recently talked with Lewis to discuss her work, and to learn more about how parents and caregivers can get their children more sleep.
This conversation has been edited and condensed for clarity.
CNN: What prompted you to write a book about teens and sleep?
Lisa Lewis: The whole issue of teen sleep and school start times hit my radar when my oldest kid, who is now in college, entered high school. At that point, the school started at 7:30 a.m. And I just knew that was much too early. I was driving him to school at that point, and every morning I’d look over and see he was not very awake. Every afternoon he was coming home really worn out.
CNN: So why do teens need so much sleep?
Lewis: At the onset of puberty, teens have a circadian rhythm shift, and their body clocks shift to a later schedule. It also connects to the release of melatonin, which is what primes our bodies to sleep. When kids become teenagers, melatonin begins to be released later than it used to. That means teens are not ready to fall asleep until 11 p.m. Because the same melatonin does not recede until later, teens end up wanting to sleep in more than they used to.
CNN: How much sleep should teens be getting?
CNN: What are the ramifications of teens not getting enough sleep?
Lewis: Sleep for teens is an emotional buffer and provides emotional resiliency. Teens are going through a major phase of brain development, and sleep is where a lot of that development happens. In the classroom, students who are asleep are not learning. Students who are there and not fully awake are not learning well. Sleep deprivation limits students from acquiring information, impedes the retention of the information, and hinders the ability to retrieve that information.
CNN: Beside early start times, what are some other external factors that can disrupt teen sleep?
CNN: How do you think the chaos of the pandemic years has impacted teen sleep?
CNN: How can parents and caregivers convince teenagers they need more sleep?
Lewis: Lecturing them doesn’t have the desired effect. Having a conversation is more helpful, especially if it’s an ongoing conversation. Model good behaviors, like no tech use within one hour of bedtime. Teach them about things like a wind-down routine. Our brains are not like computers — you don’t just turn it off and hit the pillow and go to sleep. One thing that’s important is not to force any of it.
CNN: At what point did your project expand to advocacy?
CNN: Why is this new law significant?
Lewis: The new law goes into effect July 1, and it’s the first of its kind in the nation requiring healthy secondary school start times. It specifies that for public and charter middle schools, start times can be no earlier than 8 a.m., and for high schools, start times can’t be earlier than 8:30 a.m. Similar laws in other places have proven to be successful. To this point, the largest city to change its start times is Seattle; they did it in 2016. The city did all these surveys before and after that change, and they learned students got an extra 34 minutes of sleep on school nights once the start times were moved back. That’s huge.
CNN: What are the big questions you’ll be asking next?
Lewis: As of right now, California is the only state that has enacted a law of this scope. That leaves quite a bit of room to work with other states out there. As of right now, both New York and New Jersey have active bills on this topic, but no other state has passed a law like this. There is a tremendous opportunity to look at doing this in all the other states; teen sleep deprivation is not just a California issue. This is something I will be focusing on for quite a bit.
Matt Villano is a writer and editor based in California. His work has appeared in The New York Times, CNN and elsewhere.
Correction: An earlier condensed version of this story has been corrected to accurately reflect Lewis’ comments on circadian sleep rhythm. The previous version of this story also misstated the month the CDC released new data on mental health and teens. An update to the story also clarified which of the state’s education committees Lewis testified in front of.File source