Changing Times: Findings From the First Longitudinal Study of Later High School Start Times

In the early 1990s, medical research found that teenagers have biologically different sleep and wake patterns than the preadolescent or adult population. On the basis of that information, in 1997 the seven comprehensive high schools in the Minneapolis Public School District shifted the school start time from 7:15 a.m. to 8:40 a.m. This article examines that change, finding significant benefits such as improved attendance and enrollment rates, less sleeping in class, and less student-reported depression. Policy implications are briefly discussed, acknowledging this to be a highly charged issue in school districts across the United States. Recent research information about the sleep needs of adolescents and the influence of sleep on learning and behavior has captured the attention of school districts across the United States. Physicians, parents, school board members, and others are asking school administrators and policymakers to acknowledge the medical evidence about the biological sleep patterns of teenagers and to adjust school schedules accordingly. The discussions and debates have been intense because this is a multifaceted issue. School administrators are being asked to weigh the factual information about the biology of adolescents’ sleep patterns against the competing demands of teachers’ work preferences, athletic and afterschool activity schedules, and bus transportation schedules. This article presents findings from a 4-year study in a large, urban school district that altered high school start times significantly from 7:15 a.m. to 8:40 a.m. This change affected more than 12,000 secondary students within a total K‐12 population of nearly 51,000 students. Theoretical Perspectives