SleepNCT06657482
Effects of Delayed School Start Times on Sleep, Mental Health, and Academic Performance Among Norwegian Adolescents
A study testing Delayed school start time in people with Sleep and Sleep Disorders, Circadian Rhythm, run by University of Bergen at 1 site in Norway.
Trial summary
The aim is to investigate whether later school start times have positive effects on high school students' sleep patterns, mental health and daytime functioning. Read more about this study
- Who is it for?
- Any ageHealthy volunteers can take part
- Conditions the study is for
- Sleep, Sleep Disorders, Circadian Rhythm, Psychiatric Disorder
- What is being tested?
- Delayed school start time
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 583 participants
- Where
- 1 siteNorway
- Study dates
- 15 Aug 2023to 30 Jun 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- 1st year high school students at study preparatory program of participating schools
Who cannot join
- Parent consent not obtained/documented for participants under 16 years
Trial locations and contacts
1 site in 1 country.
About this study
The aim is to investigate whether later school start times have positive effects on high school students' sleep patterns, mental health and daytime functioning.
Read the detailed description
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.
- Being tested
- Delayed school start time
- Medical subject headings
- Sleep Disorders, Circadian Rhythm, Mental Disorders, Disorders of Excessive Somnolence
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Delayed school start timeBehavioural
The intervention group will start school two hours later on Mondays (at 10.15 ± 15 min) and one hour later on Tuesdays (9.15 ± 15 min) and to ordinary school start time (8.15 ± 15 min) for the rest of the week
| Study group | Role | What they receive |
|---|---|---|
| Delayed school start times on Mondays and Tuesdays (intervention condition) | Experimental | Two hour delay in school start time on Mondays and one hour delay on Tuesdays. Ordinary school start time (8:15 ± 15 min) for the rest of the week. Receives: Behavioral: Delayed school start time |
| Ordinary school start time all weekdays (control condition) | No intervention | Ordinary school start time (8:15 ± 15 min) all school days |
What is being measured
The primary outcome is the main question the study is designed to answer.
Average sleep duration on school days
Average sleep duration across the arms will be calculated using the Munich ChronoType Questionnaire (MCTQ), adjusted for nocturnal awakenings
Measured: Baseline and at the end of the school year (at about 8 months follow-up)
Preferred school start time (late vs. early Mondays and Tuesdays)
A conditioned item asking how satisfied the students are starting early or later on Mondays and Tuesdays, or ranging from "Very satisfied" to "very dissatisfied", will be included.
Measured: At the end of the school year (at about 8 months follow-up)
Daytime sleepiness on school days
Daytime sleepiness will be assessed based on the Karolinska Sleepiness Scale (KSS; adjusted to target sleepiness on each weekday) and The Chinese adolescent daytime sleepiness scale (CADSS).
Measured: CADSS: Baseline and at the end of the school year (at about 8 months follow-up). KSS: At the end of the school year (at about 8 months follow-up)-up
Secondary outcomes (4)
School absence and academic performance (self-reported and objective)
Data gathered from school authorities.
Measured: Self-reported data: Baseline and end of school year. Objective data: At the end of the school year (at about 8 months follow-up)-up
Mental health
Anxiety and depression will be assessed during the past two weeks using the Generalized Anxiety Disorder-7 and the Patient Health Questionnaire-9, respectively.
Measured: Baseline and at the end of the school year (at about 8 months follow-up)
Social jetlag
Social jetlag, calculated as the discrepancy in sleep timing on free vs. weekdays, will be calculated based on the MCTQ
Measured: Baseline and at the end of the school year (at about 8 months follow-up)
Sleep duration, school days with early vs. late start
Sleep duration for late starting days will be compared with early starting days
Measured: At the end of the school year (at about 8 months follow-up)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Oct 2024
- Study start15 Aug 2023
- Primary completion30 Jun 2025
- Study completion30 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SleepStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 583 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Bergen
- Sponsor type
- University, hospital or other
- Collaborators
- Haukeland University Hospital
- Responsible party
- Sponsor
- Investigators
- Bjørn Bjorvatn, Principal investigator, Department of Global Public Health and Primary Care, University of Bergen, Norway
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06657482
- Sponsor's protocol ID
- REK Vest 606094
- Status last verified
- Apr 2026
- First submitted
- 3 Jul 2024
- Last updated
- 1 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Delayed School Start Times on Sleep, Mental Health, and Academic Performance Among Norwegian Adolescents
- ClinicalTrials.gov ID
- NCT06657482
- Acronym / sponsor ID
- REK Vest 606094
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 583 participants (actual)
- Lead sponsor
- University of BergenUniversity, hospital or other
- Collaborators
- Haukeland University Hospital
- Study start
- 15 Aug 2023 (actual)
- Primary completion
- 30 Jun 2025 (actual)
- Study completion
- 30 Jun 2025 (actual)
- First posted
- 24 Oct 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim is to investigate whether later school start times have positive effects on high school students' sleep patterns, mental health and daytime functioning.
Detailed description
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.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Delayed school start times on Mondays and Tuesdays (intervention condition) | Experimental | Behavioral: Delayed school start timeTwo hour delay in school start time on Mondays and one hour delay on Tuesdays. Ordinary school start time (8:15 ± 15 min) for the rest of the week. |
| Ordinary school start time all weekdays (control condition) | No intervention | –Ordinary school start time (8:15 ± 15 min) all school days |
Who may qualify
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (1 listed)
- 1st year high school students at study preparatory program of participating schools
Key exclusion criteria (1 listed)
- Parent consent not obtained/documented for participants under 16 years
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Delayed school start timeThe intervention group will start school two hours later on Mondays (at 10.15 ± 15 min) and one hour later on Tuesdays (9.15 ± 15 min) and to ordinary school start time (8.15 ± 15 min) for the rest of the week | Behavioural | Delayed school start times on Mondays and Tuesdays (intervention condition) |
Primary outcome
Average sleep duration on school days
Time frame: Baseline and at the end of the school year (at about 8 months follow-up)
Average sleep duration across the arms will be calculated using the Munich ChronoType Questionnaire (MCTQ), adjusted for nocturnal awakenings
Preferred school start time (late vs. early Mondays and Tuesdays)
Time frame: At the end of the school year (at about 8 months follow-up)
A conditioned item asking how satisfied the students are starting early or later on Mondays and Tuesdays, or ranging from "Very satisfied" to "very dissatisfied", will be included.
Daytime sleepiness on school days
Time frame: CADSS: Baseline and at the end of the school year (at about 8 months follow-up). KSS: At the end of the school year (at about 8 months follow-up)-up
Daytime sleepiness will be assessed based on the Karolinska Sleepiness Scale (KSS; adjusted to target sleepiness on each weekday) and The Chinese adolescent daytime sleepiness scale (CADSS).
4 secondary outcomes
School absence and academic performance (self-reported and objective)
Time frame: Self-reported data: Baseline and end of school year. Objective data: At the end of the school year (at about 8 months follow-up)-up
Mental health
Time frame: Baseline and at the end of the school year (at about 8 months follow-up)
Social jetlag
Time frame: Baseline and at the end of the school year (at about 8 months follow-up)
Sleep duration, school days with early vs. late start
Time frame: At the end of the school year (at about 8 months follow-up)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 May 2026.
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Healthy Adult Participants
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Bjørn Bjorvatn principal investigator
Department of Global Public Health and Primary Care, University of Bergen, Norway
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Delayed school start time in people with Sleep and Sleep Disorders, Circadian Rhythm, run by University of Bergen at 1 site in Norway.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 1 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Norway. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Average sleep duration on school days (time frame: Baseline and at the end of the school year (at about 8 months follow-up)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 May 2026.