Sleep related problems, circadian preference and scholastic achievement: a study on a representative sample of Italian eight grade students

Objectives: In the present study sleep habits, sleep related problems and circadian preference (morningness/eveningness dimension) were investigated in a representative sample of Italian eighth grade students. We further evaluate the influence of these sleep related variables on scholastic achievement. Methods: We analyzed data of 3391 students that participated to the Trends in International Mathematics and Science Study. All participants completed a modified version of School Sleep Habits Survey to measure schooldays and weekends sleep habits, daytime sleepiness, sleep problems, and circadian preference. Results: Results indicated a very high frequency of sleep complaints. Eight grade students reported frequent difficulties in awakenings, as well as frequent episodes of daytime sleepiness, particularly during studying. The Circadian Preference was correlated with self-reported sleep problems and daytime sleepiness, indicating that an evening orientation is associated to poor sleep quality and higher daytime sleepiness in this age group. With respect to scholastic achievement, the grades in Maths and Italian subjects were significantly associated with sleep problems, daytime sleepiness and, to a lesser extent, with circadian preference. Conclusions: This results not only corroborates the role of sleep on cognitive performance, but they underline a significant presence of sleep problems even at this age.