Starting school just thirty minutes later at a private high school in Rhode Island resulted in better moods, more alert, and less depressed students. They were also more likely to attend class. The study, published in the July issue of Archives of Pediatrics & Adolescent Medicine bolsters evidence that teens have special sleep needs.
About 200 students in grades 9 through 12 at St. George’s School in Newport filled out on-line questionnaires on their sleep habits both before and after the school changed its start time from 8 am to 8:30 am on January 6, 2009. The proportion of students getting at least eight hours of sleep a night jumped from 16.4% to 54.7%. Those getting less than seven hours decreased by almost 80%.
Students reported less daytime sleepiness, improved mood and depression symptoms, and increased interest and motivation to participate in academic and athletic activities. Absences during first period declined and fewer students visited the health center with complaints of fatigue.
Head administrator Eric Peterson also noticed that the teachers were “less frantic” at the start of the day and that everyone at the school ate a healthier breakfast as a result of improved alertness.
The experiment was so successful among all students and faculty members that the school never went back to starting school at 8 am, according to lead author Dr. Judith Owens, pediatric sleep researcher at Hasbro Children’s Hospital.
"Mornings are so much more pleasant at my house I can't even begin to tell you," said Owens, whose daughter participated in the experiment. "Many of the faculty members said the same thing: that it improved the quality of their lives as well as the perception that students were just better rested and more ready to start the day."
Sleep medicine specialist have long known that the circadian rhythm of adolescents is different than that of either children or adults, says Dr. Heidi V. Connolly, chief of the division of pediatric sleep medicine at the University of Rochester Medical Center in New York. There is as much as a two hour shift in sleep-wake cycles that occurs during puberty, she adds.
Teens also need more sleep at night than adults – 9 to 9 ¼ hours. Sleep deprivation is especially harmful to parts of the brain that need to develop in adolescence — those involving motivation, judgment and emotional regulation. Less sleep is also associated with a number of bad outcomes for teens, including obesity, an increase in car accidents and attention and memory problems.
Research into changing high school start times to accommodate the teens circadian rhythm change began in Minnesota 13 years ago and resulted in the Minneapolis Public School District changing the start time of high schools to 8:40 am and middle schools to 9:10 am, according to an accompanying journal editorial written by Kyla Wahlstrom PhD of the University of Minnesota.
There, the school system has documented such positive effects as higher SAT scores and fewer car crashes.