School start time effects on adolescent learning and academic performance, emotional health and behaviour.
Level 5 - mechanism / opinion, no new human data
Narrative review without systematic methodology
PubMed 28858008 · doi:10.1097/YCO.0000000000000368
What was done
This narrative review examined cross-disciplinary literature from medical and educational fields regarding the effects of school start times on adolescent sleep duration, academic outcomes, emotional health, and risk-taking behaviors.
What was found
The abstract reports no numerical data, sample sizes, or statistical effect estimates. It defines adolescent sleep deficiency as less than 8 hours per night. It describes that adolescents with sleep deficits from early school start times have higher rates of depressive symptoms, substance use (drugs, cigarettes, and alcohol), lower grades, and greater risk of motor vehicle crashes compared to those with later start times.
Why it matters
The paper frames early school start times as a modifiable public health issue that conflicts with the normal adolescent circadian phase delay.
Limits
The abstract describes a non-systematic narrative review with no defined search criteria, risk-of-bias assessment, or quantitative synthesis. No primary study counts, sample sizes, or specific effect magnitudes are provided in the abstract.
Cited by
- partial A University of Minnesota study found that delaying high school start times by 1 hour improved student grades by a full letter grade.