Sleep habits, circadian preference, and school performance in early adolescents.

OBJECTIVE: This study aimed to cast light on the relationships between sleep habits, perceived sleep problems and school performance in Evening-type (E-type) compared with Morning-type (M-type) early adolescents.

METHODS: Comparison of questionnaire data of E-type and M-type adolescents random-selected from a large sample of eight-grade adolescents who took part in a national survey of competence in mathematics and science.

RESULTS: The proportions of sleep problems that were observed to occur more than once per week and the frequency of struggling to fall asleep and/or falling asleep in distinct everyday situations were much higher in E-type than in M-type adolescents. Moreover, E-type adolescents showed more disturbed and poorer sleep during both school and weekend days and reported lower grades in mathematics, science and Italian.

CONCLUSIONS: E-type adolescents showed a partial recovery of sleep debt during weekend days. This finding suggests that they could improve their school performance if tests and classwork would be scheduled on their most alert school days, namely the post-weekend ones.