Circadian RhythmsNCT07317349
The Effect of a Continuous 1-Hour Time Delay on Circadian Rhythms
A study testing Fixed daily routine and Daily time delay in people with Circadian Rhythms and Time Perception, run by University of Aarhus at 1 site in Denmark.
Trial summary
The purpose of this study is to investigate whether the experience of a daily time delay can affect our internal circadian rhythm. Read more about this study
- Who is it for?
- Ages 23 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Circadian Rhythms, Time Perception, Sleep
- What is being tested?
- Fixed daily routine and Daily time delay
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteDenmark
- Study dates
- 20 Dec 2025to 30 Aug 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 23 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy adults aged 23-45 years
- Part of a heterosexual, cohabiting couple willing to participate together in a five-day in-laboratory study
- Both partners meet all inclusion criteria
- Completion of at least upper-secondary education
- Maintain a regular sleep-wake schedule
- Habitual sleep timing within a normative range (non-extreme chronotype), assessed using the Morningness-Eveningness Questionnaire (MEQ) or the Munich Chronotype Questionnaire (MCTQ)
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- Both partners fall within the acceptable chronotype range to ensure aligned sleep-wake patterns
- Low seasonality scores on the Seasonal Pattern Assessment Questionnaire (SPAQ)
- Free from underlying sleep or mood disorders
Who cannot join
- Engages in night-shift work or maintains an irregular work or sleep schedule
- International travel involving a time-zone change of more than two hours within the past two months, or anticipated travel before study completion
- Diagnosed neurological, psychiatric, or sleep disorder (e.g., insomnia, sleep apnea, bipolar disorder)
- High risk of sleep apnea, defined as a Berlin Questionnaire score >2 (Lauritzen et al., 2018)
- Use of medications known to affect sleep, alertness, melatonin secretion, or circadian timing
- Unable or unwilling to comply with behavioral restrictions, including refraining from electronic devices displaying time cues unless clocks are removed and devices are disconnected from Wi-Fi
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- Unable or unwilling to comply with consumption restrictions, including abstaining from caffeine, alcohol, and melatonin-rich foods during the study
- Extreme chronotype, defined as a habitual midsleep time outside 03:00-05:00 on the MCTQ or classification as an extreme morning or extreme evening type on the MEQ
- Daily caffeine consumption exceeding 400 mg (approximately 4-5 cups of coffee)
- Current smoker or smoking within the past six months
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Alisha Guyett, PhD contact
Denmark1 site, 1 recruiting
- Recruiting
Aarhus University, Department of Psychology and Behavioural Sciences
Aarhus, 8000
Alisha Guyett Guyett, PhD, +4587152078, alisha.guyett@psy.au.dk
Ali Amidi, PhD
About this study
The purpose of this study is to investigate whether the experience of a daily time delay can affect our internal circadian rhythm.
- Conditions
- Circadian Rhythms, Time Perception, Sleep
- Being tested
- Fixed daily routine, Daily time delay
- Keywords
- circadian phase delay, Healthy adults
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Fixed daily routineBehavioural
All activities occur at the same time every day
Daily time delayBehavioural
All activities will be delayed by one hour per day over a 5 day period.
| Study group | Role | What they receive |
|---|---|---|
| Fixed daily routine | Experimental | All activities occur at the same time every day. During the five days, participants will have to complete various daily tests and also be asked to provide 8 saliva samples during days 1, 3, and 5 Receives: Behavioral: Fixed daily routine |
| Daily time delay of 1 hour | Experimental | All activities will be delayed by one hour. During the five days, participants will have to complete various daily tests and also be asked to provide 8 saliva samples during days 1, 3, and 5 Receives: Behavioral: Daily time delay |
What is being measured
The primary outcome is the main question the study is designed to answer.
Phase shift in circadian rhythm markers
The primary outcome is the timing of dim light melatonin onset, a marker of circadian phase. Saliva samples will be collected at regular intervals under dim light, and the time when melatonin exceeds 3 pg/mL will be recorded for each participant. This allows measurement of circadian phase shifts across conditions.
Measured: Comparing samples on days 1, 3, 5
Secondary outcomes (1)
Psychomotor Vigilance Task (PVT) Median Reaction Time
Median reaction time (milliseconds) on a brief psychomotor vigilance task (PVT) six times each day. Participants respond as quickly as possible to visual stimuli presented at random inter-stimulus intervals. For each block, the median reaction time is computed; additional indices such as lapses (responses > 500 ms) may be derived. Changes in PVT performance across the the 5 days are analysed in relation to circadian phase.
Measured: Performance will be measured at regular intervals on days 1 - 5 to track changes over the course of the study.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jan 2026
- Study start20 Dec 2025 (estimated)
- Primary completion1 Mar 2027 (estimated)
- Study completion30 Aug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Circadian RhythmsStudies 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Single group
- Model description
- Participating couples will need to live in this environment for 5 consecutive days. By lottery draw, you as a couple will either be exposed to a fixed daily routine, where all activities occur at the same time every day, or a daily time delay of 1 hour, where all activities will be delayed by one hour.
- Masking
- None (open label)
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Aarhus
- Sponsor type
- University, hospital or other
- Collaborators
- Independent Research Fund Denmark
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07317349
- Sponsor's protocol ID
- 1-10-72-143-25
- Other IDs
- 10.46540/425600108B
- Status last verified
- Dec 2025
- First submitted
- 19 Dec 2025
- Last updated
- 16 Jan 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data (IPD) underlying the published results will be shared with other researchers upon reasonable request, in accordance with Danish data protection regulations, institutional policies, and ethics approval. Data will be pseudonymised before sharing and no direct identifiers (e.g., name, contact details, personal ID numbers) will be included. Any data elements that could reasonably lead to re-identification in combination with other information will be removed or aggregated where necessary.
Study at a glance
From the registry record, last updated by the sponsor on 16 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of a Continuous 1-Hour Time Delay on Circadian Rhythms
- ClinicalTrials.gov ID
- NCT07317349
- Acronym / sponsor ID
- 1-10-72-143-25
- Conditions
- Circadian Rhythms, Time Perception, Sleep
- Keywords
- circadian phase delay, Healthy adults
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- University of AarhusUniversity, hospital or other
- Collaborators
- Independent Research Fund Denmark
- Study start
- 20 Dec 2025 (estimated)
- Primary completion
- 1 Mar 2027 (estimated)
- Study completion
- 30 Aug 2027 (estimated)
- First posted
- 5 Jan 2026 (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 purpose of this study is to investigate whether the experience of a daily time delay can affect our internal circadian rhythm.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Participating couples will need to live in this environment for 5 consecutive days. By lottery draw, you as a couple will either be exposed to a fixed daily routine, where all activities occur at the same time every day, or a daily time delay of 1 hour, where all activities will be delayed by one hour.
| Arm | Type | Receives |
|---|---|---|
| Fixed daily routine | Experimental | Behavioral: Fixed daily routineAll activities occur at the same time every day. During the five days, participants will have to complete various daily tests and also be asked to provide 8 saliva samples during days 1, 3, and 5 |
| Daily time delay of 1 hour | Experimental | Behavioral: Daily time delayAll activities will be delayed by one hour. During the five days, participants will have to complete various daily tests and also be asked to provide 8 saliva samples during days 1, 3, and 5 |
Who may qualify
- Ages
- 23 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (9 listed)
- Healthy adults aged 23-45 years
- Part of a heterosexual, cohabiting couple willing to participate together in a five-day in-laboratory study
- Both partners meet all inclusion criteria
- Completion of at least upper-secondary education
- Maintain a regular sleep-wake schedule
Key exclusion criteria (10 listed)
- Engages in night-shift work or maintains an irregular work or sleep schedule
- International travel involving a time-zone change of more than two hours within the past two months, or anticipated travel before study completion
- Diagnosed neurological, psychiatric, or sleep disorder (e.g., insomnia, sleep apnea, bipolar disorder)
- High risk of sleep apnea, defined as a Berlin Questionnaire score >2 (Lauritzen et al., 2018)
- Use of medications known to affect sleep, alertness, melatonin secretion, or circadian timing
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 |
|---|---|---|
| Fixed daily routineAll activities occur at the same time every day | Behavioural | Fixed daily routine |
| Daily time delayAll activities will be delayed by one hour per day over a 5 day period. | Behavioural | Daily time delay of 1 hour |
Primary outcome
Phase shift in circadian rhythm markers
Time frame: Comparing samples on days 1, 3, 5
The primary outcome is the timing of dim light melatonin onset, a marker of circadian phase. Saliva samples will be collected at regular intervals under dim light, and the time when melatonin exceeds 3 pg/mL will be recorded for each participant. This allows measurement of circadian phase shifts across conditions.
1 secondary outcome
Psychomotor Vigilance Task (PVT) Median Reaction Time
Time frame: Performance will be measured at regular intervals on days 1 - 5 to track changes over the course of the study.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Jan 2026.
- Sleep \& Circadian Psychology Research Unit - Aarhus University (information on research in sleep, circadian rhythms)Link provided by the sponsor.
- Individual participant dataSharing planned: Yes. De-identified individual participant data (IPD) underlying the published results will be shared with other researchers upon reasonable request, in accordance with Danish data protection regulations, institutional policies, and ethics approval. Data will be pseudonymised before sharing and no direct identifiers (e.g., name, contact details, personal ID numbers) will be included. Any data elements that could reasonably lead to re-identification in combination with other information will be removed or aggregated where necessary.
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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.
Alisha Guyett, PhD contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Fixed daily routine and Daily time delay in people with Circadian Rhythms and Time Perception, run by University of Aarhus at 1 site in Denmark.
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 9 inclusion and 10 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: looking for participants now, as of the sponsor's last update on 16 Jan 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 Denmark. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ali Amidi, PhD (+4587165305, ali@psy.au.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Phase shift in circadian rhythm markers (time frame: Comparing samples on days 1, 3, 5). 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 16 Jan 2026.