Sleepy teens haven’t got circadian rhythm
By Nathan Seppa
High schools that begin classes as early as 7:30 a.m. deprive teenagers of sleep, and attempts to reset an adolescent’s biological clock fail to solve the problem, a study in the June Pediatrics finds.
Sixty high school students in Evanston, Ill., recorded their sleep times in diaries in August, September, and November of 1997 and in February 1998. The diaries showed that students stayed up late in August but still managed to sleep 8 to 9 hours. When school started, they continued staying up late but had to awaken early for school, says Margarita L. Dubocovich, a neuropharmacologist at Northwestern University in Evanston. The teens’ average sleep fell to 6 to 7 hours on weekdays.