Reduced Sleep On School Nights Begins In Early Adolescence

The study, authored by Stephanie Apollon, Amy Wolfson and colleagues of the College of the Holy Cross in Worcester, Mass., focused on 96 seventh graders who completed the School Sleep Habits Questionnaire (school/weekend sleep variables, caffeine use) and assessed sleep for seven days via diaries and actigraphy. Twenty-five percent of the students were from families with incomes below $20,000. Effects of sex, family income, and access to health care were analyzed.

According to the results, 37 percent of the seventh graders were falling asleep after 11 p.m. with 66 percent getting less than nine hours on school nights. Family incomes below $40,000 were significantly associated with more delayed sleep patterns, particularly on weekends, and increased caffeine use. Although income was not significantly associated with health care provider use, seventh graders who had regular contact with a health care provider had healthier school-night sleep patterns than those without health care (e.g., 25 minutes more sleep, 30 min. earlier bed times, less delayed sleep schedules).

"These findings demonstrate that the trend for delays and reductions of school-night sleep begin early in adolescence, even with delayed school start times," said Amy R. Wolfson, PhD, of the College of the Holy Cross in Worcester, Mass., who developed the concept for this study that is funded by NICHD. "Other demographic factors exacerbate young adolescents' sleep patterns. Middle schoolers from families with either low income or poor access to physicians obtained less sleep, had more delayed schedules, and reported more frequent caffeine use."

It is recommended that adolescents get nine hours of nightly sleep.