California Students Sleep More, Score Higher After Law

California teenagers are finally getting the sleep they need, and it's making a real difference in their lives.

One year after the state required middle schools to start no earlier than 8 a.m. and high schools no earlier than 8:30 a.m., students are sleeping more, reporting better mental health, and scoring higher in math and English. The 2022 law made California the first state in the nation to mandate later start times.

The results are impressive. The share of students getting at least eight hours of sleep each night jumped by 13%. That's the minimum amount health experts recommend for teenagers.

The academic gains were strongest among Hispanic students and economically disadvantaged students, who often struggle most with getting enough sleep due to family and work responsibilities. Eighth graders showed measurable improvements in both math and English scores.

Mental health improvements were striking too. Boys reported the biggest drops in sadness, hopelessness, and suicidal thoughts. Hispanic students saw the largest decrease in concentration difficulties.

"The first step in addressing student mental health problems is to not create them in the first place," said Terra Ziporyn, executive director at nonprofit Start Schools Later. "Systematically depriving an entire adolescent population of adequate sleep is a surefire way to hurt their mental health."

The new study from the National Bureau of Economic Research tracked changes from 2022 through 2025. Researchers found that while some students did go to bed slightly later, they were sleeping in more in the morning, leading to overall sleep gains.

Some parents worried the change would disrupt work commutes and push back sports schedules. The study found those activities did shift later, but the changes were small.

The Ripple Effect

California's bold move is creating a blueprint for the entire nation. As the only state with a mandate like this, California proved that later start times aren't just a budget negotiation item but a public health necessity.

The success is already inspiring other states to consider similar laws. Researchers say the improvements in sleep, mental health, and academic performance demonstrate that respecting teenagers' biological sleep needs pays off in measurable ways.

While some districts struggled with the transition costs and logistics, advocates say better guidance and family involvement could smooth the path for other communities. The benefits to students make the effort worthwhile.

University of Pittsburgh researcher Osea Giuntella, who led the study, noted that later start times address just one piece of the sleep puzzle, but it's an important institutional change that schools can control.

California's teenagers are proving that when schools work with biology instead of against it, everyone wins.