Teens More Alert When School Starts Later

Study Shows Later Start Time for High School Can Improve Students' Mood and Motivation

Reviewed by Louise Chang, MD on July 06, 2010
From the WebMD Archives

July 6, 2010 -- A simple half-hour delay in high school start time led to a significant improvement in students' mood, alertness, and motivation, and increased their average sleep time during the week, according to a new study.

Judith A. Owens, MD, MPH, at the Hasbro Children's Hospital in Providence, R.I., and colleagues studied 201 students in grades nine through 12 attending a Rhode Island high school where the class start time was changed from 8 a.m. to 8:30 a.m. for a two-month period. Students completed online surveys before the change in class time and then after.

Owens and her team found that:

  • The percentage of students getting less than seven hours of sleep per night dropped by 79.4%.
  • Students reporting at least eight hours of sleep per night increased from 16.4% at the start of the study to 54.7% after two months.
  • The percentage of students who reported feeling at least somewhat unhappy or depressed dropped from 65.8% to 45.1%.
  • The percentage of students who reported feeling annoyed or irritated throughout the day also dropped, from 84% to 62.6%.
  • Reports of visiting a health center for fatigue-related symptoms decreased from 15.3% to 4.6%.
  • Sleep duration increased on school nights by about 45 minutes and the average bedtime on school nights was 18 minutes earlier.

The findings are published in the July issue of Archives of Pediatrics & Adolescent Medicine.

Debate Over School Start Times

Adjusting school times for adolescents is a controversial topic because some experts argue that a later class start time will result in students going to bed later and exacerbate the cycle of getting too little sleep.The researchers note that a later class start time led to the opposite effect -- kids went to bed a little earlier and their overall sleep quality and duration improved.

"The results of this study," they write, "add to the growing literature supporting the potential benefits of adjusting school schedules to adolescents' sleep needs, circadian rhythm, and developmental stage and of optimizing sleep and alertness in learning environments."

The researchers write that the school faculty did not favor the delayed class start time, but after seeing the students' change in attitude and performance, everyone had a change of heart. "Despite the initial considerable resistance voiced by the faculty and athletic coaches to instituting the start time delay and the original intentions of the school administration to return to the 8 a.m. start time after the trial period, students and faculty overwhelmingly voted to retain the 8:30 a.m. start for the spring term," the researchers write.

In an editorial published along with the study, Kyla Wahlstrom, PhD, from the University of Minnesota in St. Paul, writes that although Hasbro and her team's findings echo the results from earlier studies, schools are not jumping to adjust their schedules.

"The role of data and factual information in discussing and advocating for changing school start times is key. ... When the first findings emerged in 1997, the question remaining at that time concerned the effect of the later start time on academic outcomes," Wahlstrom writes. "Longitudinal research has since found several significant academic effects, such as decreasing the dropout rate, but a direct correlation between later start time and academic achievement on normed tests has not been substantiated."

"In the end, having comprehensive information and impartial presentation of what is known, and not assumed, is needed to really begin the local dialogue," Wahlstrom concludes. "The community at large is, after all, the final arbiter, as all must truly live with the consequences. Our teenagers need and deserve our best informed thinking about all of this; having the facts in hand is the best place to start."

Show Sources


News release, Archives of Pediatrics & Adolescent Medicine.

Hasbro, Archives of Pediatrics & Adolescent Medicine, 2010; vol 164: pp 608-614.

Wahlstrom, K. Archives of Pediatrics & Adolescent Medicine, 2010; vol 164: pp 676-677.

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