School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: A Review of the Literature

BACKGROUND: Insufficient sleep in adolescents has been shown to be associated with a wide variety of adverse outcomes, from poor mental and physical health to behavioral problems and lower academic grades. However, most high school students do not get sufficient sleep. Delaying school start times for adolescents has been proposed as a policy change to address insufficient sleep in this population and potentially to improve students' academic performance, reduce engagement in risk behaviors, and improve health. METHODS: This article reviews 38 reports examining the association between school start times, sleep, and other outcomes among adolescent students. RESULTS: Most studies reviewed provide evidence that delaying school start time increases weeknight sleep duration among adolescents, primarily by delaying rise times. Most of the studies saw a significant increase in sleep duration even with relatively small delays in start times of half an hour or so. Later start times also generally correspond to improved attendance, less tardiness, less falling asleep in class, better grades, and fewer motor vehicle crashes. CONCLUSIONS: Although additional research is necessary, research results that are already available should be disseminated to stakeholders to enable the development of evidence-based school policies.