One in four American high school students now gets five hours of sleep or less on school nights. That is the finding from a new study in the Journal of the American Medical Association, which tracked sleep patterns among more than 120,000 teenagers from 2007 through 2023. The number of teens sleeping under five hours jumped from roughly 16 percent to 23 percent over that period. Severe sleep deprivation, the researchers say, is no longer a fringe problem.
The study draws on self-reported data, which has limits. People misremember. They exaggerate. But the trend line is too steep and too broad to dismiss. The share of teens sleeping fewer than seven hours rose from about 69 percent to 77 percent. That means more than three-quarters of high schoolers are running on less than the minimum recommended rest. The consequences are not abstract. Chronic sleep loss in adolescence is linked to higher rates of depression, anxiety, cardiovascular disease, and diabetes. Academic performance and concentration suffer. The damage compounds.
This is not a problem confined to vulnerable groups. The study found the decline across all demographic categories. Teenagers already dealing with depression were hit especially hard, but the pattern held everywhere. It is a population-wide shift, which points to systemic causes rather than individual failures. Phones, homework, early school start times, extracurricular pressure — the report does not single out a culprit. It does call for policy changes, specifically later school start times, which could give teens more rest, improve mental health, and boost learning.
The numbers are stark. A full eight hours of sleep on school nights is becoming rare. The study adds to a growing body of evidence that adolescent sleep loss is a public-health issue. The authors argue the findings are serious enough to justify action. Families with concerns should consult a doctor, the report says. But doctors cannot push back the first bell at a high school. That requires school boards and state legislatures.
Consider what nearly one in four teens living with severe sleep deprivation means in concrete terms. A classroom of 30 students: seven of them are getting five hours or less. They are more likely to struggle with mood disorders, to have trouble focusing, to make impulsive decisions. Their bodies are still developing. The cardiovascular and metabolic risks accumulate over years. The study does not track long-term outcomes, but other research has linked adolescent sleep loss to adult health problems.
The data runs through 2023, which means it captures the aftermath of the pandemic. Remote school, disrupted routines, more screen time — all likely worsened the trend. But the decline was already underway before COVID-19. The study covers 16 years and shows a steady erosion of sleep. It is not a blip.
Later school start times have been tested in some districts. The results show gains in attendance, grades, and student well-being. The American Academy of Pediatrics has recommended middle and high schools start no earlier than 8:30 a.m. Most do not. The JAMA study gives fresh ammunition to those pushing for change. The authors are explicit: the data justifies policy shifts. Not just awareness campaigns. Not just advice to parents. Structural changes.
The report is careful to note its limitations. Self-reported sleep is not as reliable as actigraphy or lab monitoring. But the sample is large and spans more than a decade. The pattern is consistent. Teenagers are sleeping less than they used to. The consequences are measurable. The question is what happens next.
