Abstract Mkid 80

The objective of this paper is to evaluate the effects of school schedule transition (from afternoon to morning schedule) on sleep-wake cycle and diurnal sleepiness in adolescents. Subjects consisted of 28 school children (12 boys and 16 girls, mean age 12.1 ± 1.9 years) investigated on two occasions, during two consecutive weeks in October/1997 (fourth grade – afternoon schedule) and in May/1998 (fifth grade – morning schedule). Data were collected through actigraphs, sleep diaries, sleep habits questionnaires and visual analog scales. Results indicate that students are partially sleep deprived after the transition to the morning schedule although they are able – to some extent – to advance their sleep phase during school days and weekends. Diurnal sleepiness increases in the morning schedule, particularly at the beginning of the schooldays. Number of daytime naps increases and the number of spontaneous awakenings decreases after the transition. Since the primary focus of education is to improve learning conditions and maximize students’ potentialities, school organization should take into account not only space and social aspects of school, but also temporal aspects of human biological organization, specially at this particular age. These temporal aspects seem to be particularly relevant when school schedule changes are envisaged.