Based on the assumption that teenagers have a natural sleep cycle that begins late and ends later in the morning, Kyla and her team asserts that teens beginning school at 7:15 am are more likely to suffer from depression, experience parental and peer stress, and are more prone to use illegal substances (Wahlstrom 2002). She theorizes that if start time for high school students was pushed to 8:00 in the morning, students would experience decreased level of depression and their overall grades in school would rise. Her objective is to prove through sufficient data collection from two districts to validate her hypothesis.
The research data was collected via survey questionnaires and interviews in two Minneapolis school districts within a one year period. The first suburban district, Edina had changed their start time to 8:30 am and the Minneapolis Public Schools District also changed their school hours to begin at 8:40 am. Both school districts provided CAREI information about their work, sleep, and school habits of over 7,000 students and over 3,000 teachers. 750 parents were interviewed with regards to their preferences and opinion about the starting time of school.
The results of the study were quite positive. Edina parents conveyed concerns with the later start time and its effects with their children's' extracurricular activities; however, after one year, 92% of the Edina parents favored the later start time (Wahlstrom 2002). In the Minneapolis schools, data showed that there was a significant decrease in drop out rates, and depression, and an increase in GPA after the implementation of the earlier start time was reported. Based on the premise that teenager's sleep cycle differs, it can be concluded that overall, teenaged students may very well benefit from a later start time in school, thus supporting Kyla's hypothesis.