Effects of Delayed School Start Times on Sleep, Mental Health, and Academic Performance Among Norwegian Adolescents

The current study is a randomized controlled study investigating whether later school start times on Mondays and Tuesdays have positive impact on high school students' sleep patterns, mental health, and daytime functioning. 1st year high school students are randomly assigned to classes starting either two hours later on Mondays and one hour later on Tuesday and ordinary school start times (8:15 ± 15 min) for the rest of the week, or to classes starting at regularly school start times (8:15 ± 15 min.) all weekdays. The students will be invited to respond to a web-based survey assessing sleep, mental health, and daytime functioning by the beginning and end of the school year. Official school grades and school absence data will be collected through the county administration for consenting students. Cognitive tests and objective sleep record through Somnofy are planned for a subgroup by the end of the 2024-25 school year. The study will last for two school years and involve two different cohorts of 1st year high school students.