Summary#1: Delayed School Start Time Associate with improvements in adolescent behavior

1.They  studied 201 students in grades 9 through 12 attending a high school in Rhode Island. The study, class start time was delayed 30 minutes, from 8 a.m. to 8:30 a.m. Students were required to complete the online retrospective Sleep Habits Survey before and after the change in school start time. The study showed that students sleeping less than seven hours of sleep decreased 79.4 %, with at least eight hours of sleep increased from 16.4 % to 54.7 %. Students unhappy or depressed decreased from 65.8 % to 45.1%, "grumpy" students also decreased from 84 % to 62.6 %. The visits to the nurse decreased from 15.3% to 4.6%. I think that the article in Science daily from Judith OWens is correct because the lack of sleeping affect the way your emotions will change later.

http://www.sciencedaily.com/releases/2010/07/100705190532.htm