Age-related changes of sleeping pattern during adolescence

A questionnaire concerning sleep-related lifestyle, and physical and mental health was administered to the students of junior high schools (12-15 year s), high schools (15-18 years), and universities. While bedtime linearly de layed with age throughout the adolescence (from junior high school to unive rsity age), rise time remained constant until high school ages. As a result , total nocturnal sleep time considerably decreased during this period. Ris e time then delayed with age in the university sample. Daytime sleepiness i ncreased with age peaking at high school age, then decreased gradually duri ng university age. Several physical and mental health conditions got worse during high school and university ages. Compared with the adolescent sample s, daytime sleepiness and mental health complaints were very low in the adu lt samples.