Sleep Duration and Daytime Drowsiness in Adolescents

By
Lu Dong
Wendy Troxel
October 12, 2026

Jama Network Open

At a Glance

Category	Detail
Condition	Sleep duration, timing, and daytime sleepiness among US youths aged 12 to 21 years
Key Mechanisms	Adolescent circadian delay can conflict with early school schedules; later school start times are associated with increased sleep.
Target Population	US youths aged 12 to 21 years, including enrolled and nonenrolled participants
Care Setting	Population-level, school-schedule context; the study compared California youths with peers elsewhere in a 2024 nationally representative survey.

Key Highlights

In a cross-sectional sample of 724 youths, mean sleep duration was 8.22 hours; 30% reported falling asleep during class or work.
California youths reported sleeping 38 minutes longer and waking 40 minutes later than youths elsewhere, with no significant bedtime or daytime-sleepiness difference.
Among middle and high school students, California youths reported 24 minutes longer sleep and woke 29 minutes later than peers elsewhere.
Older age was associated with later bedtimes and wake times, shorter sleep duration, and greater daytime sleepiness.
Black and Hispanic youths reported greater daytime sleepiness than non-Hispanic White youths, without a reported reduction in sleep duration.

Guideline-Based Recommendations

Diagnosis

The study assessed sleep duration from reported bedtime and wake time and assessed daytime sleepiness with a 4-point question.

Management

The article identifies later school start times as a modifiable population-level lever for adolescent sleep; it does not provide individual treatment recommendations.

Monitoring & Follow-up

The study measured bedtime, wake time, sleep duration, and daytime sleepiness; it did not specify clinical monitoring guidance.

Risks

The authors note limitations including cross-sectional, self-reported data, no premandate AYP data, few respondents directly targeted by SB 328, and possible confounding by other California-specific factors.

Patient & Prescribing Data

The analytic cohort included 724 US youths aged 12 to 21 years; mean age was 16.3 years, and 78% reported school enrollment.

No medication or individual treatment was evaluated. California's SB 328 requires public high schools to start at 8:30 am or later and middle schools at 8:00 am or later, with rural districts exempt.

Clinical Best Practices

Interpret the California comparisons as observational associations, not proof that SB 328 caused the observed differences.
Consider that the reported sleep-duration difference between California and other states was associated with later wake times, while bedtimes did not differ.
Note that daytime sleepiness did not differ significantly between California youths and peers elsewhere, despite differences in sleep duration and wake time.