Among the responses proposed to alleviate adolescent sleep problems, some school districts have considered changing their school starting times. Workshop participants learned of research in the Minneapolis metropolitan area on attitudes toward such a change and preliminary findings from schools that actually implemented later starting times. During the 1996-1997 school year in Edina, Minnesota (a suburb of Minneapolis), the high school day shifted from a 7:20 a.m. start to 8:30. In the following school year the Minneapolis Public Schools changed the starting time from 7:15 to 8:40 a.m. at seven of its high schools. Kyla Wahlstrom, associate director of the Center for Applied Research and Educational Improvement of the University of Minnesota, reviewed early findings from studies of these schools as well as data collected in surveys and focus groups involving key stakeholders, including students, teachers, and parents (Wahlstrom and Freeman, 1997; Kubow et al., 1999).

The schools studied represent different socioeconomic groups and levels of diversity among student populations. In Minneapolis the schools were in an urban, low-income setting with 12,000 students, including a large immigrant population, where half of the students fail to complete high school. Suburban Edina, in contrast, has high socioeconomic levels and about 1,800 high school students. In Edina, enrollment is stable and most students go on to college.

Early findings from studies in these Minnesota schools showed that a majority of teachers reported that a greater number of students were more alert during the first two school periods than they had been with an earlier start time. Slightly more than half said they saw fewer students sleeping at their desks. In Minneapolis, teachers were evenly divided about whether student behavior improved. Edina teachers indicated markedly improved student behavior. School nurses and counselors also reported fewer students seeking help for physical complaints or stress. In Minneapolis schools, both teachers and students reported a drop in the number of students involved in extracurricular activities; later schedules also posed difficulties for some students who worked after school. Edina students and teachers saw no significant change in after-school activities, including work. Wahlstrom emphasized that these were early findings and that both additional data and further analysis are needed on the effects of changes in school starting times (Wahlstrom, 1999).

Wahlstrom also summarized key results from surveys conducted with more than 7,000 students in three Minnesota school districts, using the Brown University School Sleep Habits Survey. The main purpose was to discover any differences among students in one district that had changed to a later starting time and two others in which the earlier starting time was maintained. Researchers found significant differences in students' responses regarding their sleep habits. Where the later time was instituted, students reported getting a full hour more of sleep than those with the earlier starting time. These students also reported less overall sleepiness, less daytime sleepiness, and less depression, as well as higher grades than their peers in the other schools. These findings do not indicate causality—that a later starting time will cause improvement in academic grades—but do show a statistical relationship between these two variables that may be explained by such things as less struggle to stay awake in class when starting times are later.