Daytime sleepiness during transition into daylight saving time in adolescents: Are owls higher at risk?

Sleep Med. 2009 Oct;10(9):1047-50. doi: 10.1016/j.sleep.2008.08.009. Epub 2009 Apr 5.


Background: Individuals differ in their biological rhythms and preferences for time of day. Here, we looked at the transition into daylight saving time (DST) in adolescents. As adolescents tend to be evening types, one may expect that they suffer from a transition into DST.

Methods: To assess these changes, we measured daytime sleepiness and morningness-eveningness preference (CSM score) in adolescents.

Results: Daytime sleepiness correlated with age and CSM score. Older pupils and evening types showed a higher sleepiness. Daytime sleepiness was higher after the transition until the third week after. Older pupils and pupils scoring higher on eveningness reported higher daytime sleepiness after the transition, suggesting that these pupils suffer most from the change. Using cut-off scores for larks and owls, we found that owls showed higher sleepiness than larks.

Conclusion: As one consequence, class and school performance tests should not take place in the first week(s) after the transition into DST.

MeSH terms

  • Adaptation, Physiological*
  • Adolescent
  • Adolescent Behavior
  • Age Factors
  • Child
  • Circadian Rhythm*
  • Cohort Studies
  • Disorders of Excessive Somnolence / epidemiology*
  • Female
  • Germany
  • Humans
  • Male
  • Photoperiod*
  • Surveys and Questionnaires
  • Young Adult