ChronobiologyNCT04921215
Teen Sleep and Light Study
A study testing Morning bright light in people with Chronobiology and Light, run by Rush University Medical Center at 1 site in United States.
Trial summary
Circadian clocks shift later (delay) with the progression of puberty; this shift contributes to late sleep onsets in older adolescents. Early school start times, however, force teenagers to awaken earlier than their spontaneous wake time and the opportunity for sleep shortens. Read more about this study
- Who is it for?
- Ages 14 to 17 yearsHealthy volunteers can take part
- Conditions the study is for
- Chronobiology, Light, Sleep
- What is being tested?
- Morning bright light
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 88 participants
- Where
- 1 siteUnited States
- Study dates
- 14 Jun 2021to 15 Aug 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 14 to 17 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- 14-17 years old;
- Participants and parents have sufficient knowledge of the English language;
- Participants are fully vaccinated for COVID-19
Who cannot join
- personal history of a psychotic disorder, bipolar disorder, neurological disorder, psychopathology, sleep disorder (sleep apnea, restless legs syndrome, narcolepsy, insomnia), metabolic disorders, chronic medical conditions (e.g., cancer, diabetes, kidney disease, active asthma), or infectious illness;
- current illness, fever or symptoms of respiratory infection or allergy at the time of laboratory assessments;
- current use of prescribed mediations (except birth control pills);
- current use of melatonin or over-the-counter medications that can affect the sleep/wake cycle, daytime sleepiness, or suppress melatonin;
- physical handicap that interferes with the study (e.g., blind);
- mental retardation or other pervasive developmental disorder;
Show all 14Show fewer
- symptoms of depressed mood based on a score of 16 or greater on the Center for Epidemiological Studies fro Depression (CES-D);
- suicidal ideation (past or current)
- travel beyond two time zones within a month of beginning the study;
- female participants who indicate symptoms of premenstrual dysphoric disorder (PMDD)
- unusual sleep lengths (means < 6 hours or > 10 hours);
- color blind as determined by the Ishihara color blindness test, or eye surgery to correct for lens curvature;
- positive test for illicit drugs or nicotine;
- positive test for alcohol at the beginning of the 7-day lab stay
Trial locations and contacts
1 site in 1 country.
United States1 site
Rush University Medical Center, Biological Rhythms Research Laboratory
Chicago, Illinois, 60612
About this study
Official title: Adolescent Circadian Misalignment: Mechanistic Studies of Sleep and Light
Circadian clocks shift later (delay) with the progression of puberty; this shift contributes to late sleep onsets in older adolescents. Early school start times, however, force teenagers to awaken earlier than their spontaneous wake time and the opportunity for sleep shortens. Chronic circadian misalignment and sleep restriction are at their peak during late adolescence, and are associated with various negative outcomes. Morning bright light exposure from light boxes can shift rhythms earlier (phase advance) to facilitate earlier sleep onset, and reduce circadian misalignment and the associated risks. Studies of adults, however, indicate that restricted sleep and exposure to evening light due to late bedtimes make morning bright light less effective in producing advances. Pilot data collected from adolescents mimic this finding, but also suggest that staying awake late in normal household lighting and the subsequent sleep restriction before and during a 3-day morning bright light regimen, can shift the system in the wrong direction (phase delay). The overarching goal of this study is to examine the dose of sleep restriction and evening household light that prevents the desired phase advance to morning bright light in adolescents aged 14-17 years. Study 1 aims to construct a sleep restriction with normal household evening light dose-response curve to determine the point at which morning bright light begins to lose its effectiveness. The investigators hypothesize that the circadian system will advance with sufficient sleep, but with increasing sleep restriction/evening light, circadian rhythms will not shift or will delay despite the phase advancing morning bright light. Study 2 will test whether reducing evening light exposure by wearing sunglasses before bedtime during sleep restriction can facilitate phase advances. The main outcome measures to build the dose-response curve will be phase shifts of the central circadian clock marked by the dim light melatonin onset (DLMO) and total sleep time measured from actigraphy in the laboratory. Secondary outcomes include cognitive performance, sleepiness, and mood.
Read the detailed description
Circadian clocks shift later (delay) with the progression of puberty; this shift contributes to late sleep onsets in older adolescents. Early school start times, however, force teenagers to awaken earlier than their spontaneous wake time and the opportunity for sleep shortens. Indeed, a majority of adolescents in the U.S. are chronically sleep deprived, getting 1-2 hours less sleep than recommended. Also, many adolescents wake for school at the "wrong" circadian time. Chronic circadian misalignment and sleep restriction are at their peak during late adolescence, and are associated with morning daytime sleepiness, poor academic performance, conduct problems, depressed mood, suicidal ideation, substance use, and obesity. Morning bright light exposure from light boxes can shift rhythms earlier (phase advance) to facilitate earlier sleep onset, and reduce circadian misalignment and the associated risks. The investigators constructed the first phase response curve (PRC) to light for adolescents and determined that the optimal time for bright light exposure to produce phase advances was about 1 hour before habitual wake and light should be avoided around the time of habitual bedtime because it causes rhythms to shift later (delay). Studies of adults, however, indicate that restricted sleep and exposure to evening light due to late bedtimes - two classic features of older adolescent sleep - make morning bright light less effective in producing advances. Pilot data collected from adolescents mimic this finding, but also suggest that staying awake late in normal household lighting and the subsequent sleep restriction before and during a 3-day morning bright light regimen, can shift the system in the wrong direction (phase delay). The overarching goal of this study is to examine the dose of sleep restriction and evening household light that prevents the desired phase advance to morning bright light in adolescents aged 14-17 years. Study 1 aims to construct a sleep restriction with normal household evening light dose-response curve to determine the point at which morning bright light begins to lose its effectiveness. Following a baseline week with 10-hour sleep opportunities, participants will keep the same wake time but be randomly assigned to one of 4 bedtimes which will be the same or later than baseline to produce 4 levels of sleep restriction with evening light (0, 1.5, 3, or 4.5 hours). After 2 nights, the sleep schedule will gradually shift earlier over 3 nights, and participants will receive bright light each morning. The investigators hypothesize that the circadian system will advance with sufficient sleep, but with increasing sleep restriction/evening light, circadian rhythms will not shift or will delay despite the phase advancing morning bright light. Study 2 will test whether reducing evening light exposure by wearing sunglasses before bedtime during sleep restriction can facilitate phase advances. Study 2 will test the same 4 "doses" of sleep restriction. The main outcome measures to build the dose-response curve will be phase shifts of the central circadian clock marked by the dim light melatonin onset (DLMO) and total sleep time measured from actigraphy in the laboratory. Secondary outcomes include cognitive performance, sleepiness, and mood.
- Conditions
- Chronobiology, Light, Sleep, Circadian Rhythm, Adolescence
- Being tested
- Morning bright light
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Morning bright lightBehavioural
All participants will receive phase advancing morning bright light.
| Study group | Role | What they receive |
|---|---|---|
| 0 hours of sleep restriction | Active comparator | Bedtime will be the same as baseline. Receives: Behavioral: Morning bright light |
| 1.5 hours of sleep restriction | Experimental | Bedtime will be 1.5 hours later than baseline. Receives: Behavioral: Morning bright light |
| 3 hours of sleep restriction | Experimental | Bedtime will be 3 hours later than baseline. Receives: Behavioral: Morning bright light |
| 4.5 hours of sleep restriction | Experimental | Bedtime will be 4.5 hours later than baseline. Receives: Behavioral: Morning bright light |
What is being measured
The primary outcome is the main question the study is designed to answer.
Dim Light Melatonin Onset (DLMO) phase shift
Saliva sampling for the baseline DLMO will begin 8 hours before baseline bedtime and end 4 hours after baseline bedtime to capture the rise of endogenous melatonin. Sampling for the final DLMO will begin 11 hours before baseline bedtime and end 4 hours after baseline bedtime. Participants remain awake and seated in comfortable recliners in dim light, except when they need to use the adjoining restroom. Saliva samples are collected every 30 minutes using Salivettes. The samples are immediately centrifuged and frozen, and later shipped on dry ice to SolidPhase, Inc, when they are analyzed for melatonin using direct radioimmunoassay. Investigators compute the DLMO using a 4 pg/ml threshold; the time at which melatonin values surpass this threshold is the DLMO. Baseline - Final DLMO will define the phase shift of the central circadian clock.
Measured: Change in DLMO phase from baseline (before experimental manipulation on days 9) to final phase assessment (after experimental manipulation on day 15)
Sleep restriction dose
Sleep will be monitored by wrist actigraphy in the laboratory. Staff will document lights on and off times and any noticeable arousals to facilitate the most accurate sleep scoring. Actigraphy data are collected in 1-minute epochs and will be analyzed at the low sensitivity setting using Actiware 6, as this setting produces the most valid results for adolescents aged 14 to 17 years. The following variables will be computed: sleep start time, sleep end time, and total sleep time. The average total sleep time of study nights 10-14 will be used to determine the "dose" of sleep restriction each participant received. Sleep restriction dose will be defined as 10 hours - average total sleep time on study nights 10-14.
Measured: During the experimental manipulation (study nights 10-14)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jun 2021
- Study start14 Jun 2021
- Primary completion15 Aug 2025
- Study completion15 Aug 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ChronobiologyStudies 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
- Factorial
- Masking
- None (open label)
- Enrolment
- 88 participants (actual)
Sponsor and investigators
- Lead sponsor
- Rush University Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04921215
- Sponsor's protocol ID
- R01HL146772
- Status last verified
- Aug 2025
- First submitted
- 27 May 2021
- Last updated
- 2 Sep 2025
- 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 2 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Adolescent Circadian Misalignment: Mechanistic Studies of Sleep and Light
- ClinicalTrials.gov ID
- NCT04921215
- Acronym / sponsor ID
- R01HL146772
- Conditions
- Chronobiology, Light, Sleep, Circadian Rhythm, Adolescence
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 88 participants (actual)
- Lead sponsor
- Rush University Medical CenterUniversity, hospital or other
- Study start
- 14 Jun 2021 (actual)
- Primary completion
- 15 Aug 2025 (actual)
- Study completion
- 15 Aug 2025 (actual)
- First posted
- 10 Jun 2021 (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.
Circadian clocks shift later (delay) with the progression of puberty; this shift contributes to late sleep onsets in older adolescents. Early school start times, however, force teenagers to awaken earlier than their spontaneous wake time and the opportunity for sleep shortens. Chronic circadian misalignment and sleep restriction are at their peak during late adolescence, and are associated with various negative outcomes. Morning bright light exposure from light boxes can shift rhythms earlier (phase advance) to facilitate earlier sleep onset, and reduce circadian misalignment and the associated risks. Studies of adults, however, indicate that restricted sleep and exposure to evening light due to late bedtimes make morning bright light less effective in producing advances. Pilot data collected from adolescents mimic this finding, but also suggest that staying awake late in normal household lighting and the subsequent sleep restriction before and during a 3-day morning bright light regimen, can shift the system in the wrong direction (phase delay). The overarching goal of this study is to examine the dose of sleep restriction and evening household light that prevents the desired phase advance to morning bright light in adolescents aged 14-17 years. Study 1 aims to construct a sleep restriction with normal household evening light dose-response curve to determine the point at which morning bright light begins to lose its effectiveness. The investigators hypothesize that the circadian system will advance with sufficient sleep, but with increasing sleep restriction/evening light, circadian rhythms will not shift or will delay despite the phase advancing morning bright light. Study 2 will test whether reducing evening light exposure by wearing sunglasses before bedtime during sleep restriction can facilitate phase advances. The main outcome measures to build the dose-response curve will be phase shifts of the central circadian clock marked by the dim light melatonin onset (DLMO) and total sleep time measured from actigraphy in the laboratory. Secondary outcomes include cognitive performance, sleepiness, and mood.
Detailed description
Circadian clocks shift later (delay) with the progression of puberty; this shift contributes to late sleep onsets in older adolescents. Early school start times, however, force teenagers to awaken earlier than their spontaneous wake time and the opportunity for sleep shortens. Indeed, a majority of adolescents in the U.S. are chronically sleep deprived, getting 1-2 hours less sleep than recommended. Also, many adolescents wake for school at the "wrong" circadian time. Chronic circadian misalignment and sleep restriction are at their peak during late adolescence, and are associated with morning daytime sleepiness, poor academic performance, conduct problems, depressed mood, suicidal ideation, substance use, and obesity. Morning bright light exposure from light boxes can shift rhythms earlier (phase advance) to facilitate earlier sleep onset, and reduce circadian misalignment and the associated risks. The investigators constructed the first phase response curve (PRC) to light for adolescents and determined that the optimal time for bright light exposure to produce phase advances was about 1 hour before habitual wake and light should be avoided around the time of habitual bedtime because it causes rhythms to shift later (delay). Studies of adults, however, indicate that restricted sleep and exposure to evening light due to late bedtimes - two classic features of older adolescent sleep - make morning bright light less effective in producing advances. Pilot data collected from adolescents mimic this finding, but also suggest that staying awake late in normal household lighting and the subsequent sleep restriction before and during a 3-day morning bright light regimen, can shift the system in the wrong direction (phase delay). The overarching goal of this study is to examine the dose of sleep restriction and evening household light that prevents the desired phase advance to morning bright light in adolescents aged 14-17 years. Study 1 aims to construct a sleep restriction with normal household evening light dose-response curve to determine the point at which morning bright light begins to lose its effectiveness. Following a baseline week with 10-hour sleep opportunities, participants will keep the same wake time but be randomly assigned to one of 4 bedtimes which will be the same or later than baseline to produce 4 levels of sleep restriction with evening light (0, 1.5, 3, or 4.5 hours). After 2 nights, the sleep schedule will gradually shift earlier over 3 nights, and participants will receive bright light each morning. The investigators hypothesize that the circadian system will advance with sufficient sleep, but with increasing sleep restriction/evening light, circadian rhythms will not shift or will delay despite the phase advancing morning bright light. Study 2 will test whether reducing evening light exposure by wearing sunglasses before bedtime during sleep restriction can facilitate phase advances. Study 2 will test the same 4 "doses" of sleep restriction. The main outcome measures to build the dose-response curve will be phase shifts of the central circadian clock marked by the dim light melatonin onset (DLMO) and total sleep time measured from actigraphy in the laboratory. Secondary outcomes include cognitive performance, sleepiness, and mood.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| 0 hours of sleep restriction | Active comparator | Behavioral: Morning bright lightBedtime will be the same as baseline. |
| 1.5 hours of sleep restriction | Experimental | Behavioral: Morning bright lightBedtime will be 1.5 hours later than baseline. |
| 3 hours of sleep restriction | Experimental | Behavioral: Morning bright lightBedtime will be 3 hours later than baseline. |
| 4.5 hours of sleep restriction | Experimental | Behavioral: Morning bright lightBedtime will be 4.5 hours later than baseline. |
Who may qualify
- Ages
- 14 to 17 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (3 listed)
- 14-17 years old;
- Participants and parents have sufficient knowledge of the English language;
- Participants are fully vaccinated for COVID-19
Key exclusion criteria (14 listed)
- personal history of a psychotic disorder, bipolar disorder, neurological disorder, psychopathology, sleep disorder (sleep apnea, restless legs syndrome, narcolepsy, insomnia), metabolic disorders, chronic medical conditions (e.g., cancer, diabetes, kidney disease, active asthma), or infectious illness;
- current illness, fever or symptoms of respiratory infection or allergy at the time of laboratory assessments;
- current use of prescribed mediations (except birth control pills);
- current use of melatonin or over-the-counter medications that can affect the sleep/wake cycle, daytime sleepiness, or suppress melatonin;
- physical handicap that interferes with the study (e.g., blind);
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 |
|---|---|---|
| Morning bright lightAll participants will receive phase advancing morning bright light. | Behavioural | 0 hours of sleep restriction, 1.5 hours of sleep restriction, 3 hours of sleep restriction, 4.5 hours of sleep restriction |
Primary outcome
Dim Light Melatonin Onset (DLMO) phase shift
Time frame: Change in DLMO phase from baseline (before experimental manipulation on days 9) to final phase assessment (after experimental manipulation on day 15)
Saliva sampling for the baseline DLMO will begin 8 hours before baseline bedtime and end 4 hours after baseline bedtime to capture the rise of endogenous melatonin. Sampling for the final DLMO will begin 11 hours before baseline bedtime and end 4 hours after baseline bedtime. Participants remain awake and seated in comfortable recliners in dim light, except when they need to use the adjoining restroom. Saliva samples are collected every 30 minutes using Salivettes. The samples are immediately centrifuged and frozen, and later shipped on dry ice to SolidPhase, Inc, when they are analyzed for melatonin using direct radioimmunoassay. Investigators compute the DLMO using a 4 pg/ml threshold; the time at which melatonin values surpass this threshold is the DLMO. Baseline - Final DLMO will define the phase shift of the central circadian clock.
Sleep restriction dose
Time frame: During the experimental manipulation (study nights 10-14)
Sleep will be monitored by wrist actigraphy in the laboratory. Staff will document lights on and off times and any noticeable arousals to facilitate the most accurate sleep scoring. Actigraphy data are collected in 1-minute epochs and will be analyzed at the low sensitivity setting using Actiware 6, as this setting produces the most valid results for adolescents aged 14 to 17 years. The following variables will be computed: sleep start time, sleep end time, and total sleep time. The average total sleep time of study nights 10-14 will be used to determine the "dose" of sleep restriction each participant received. Sleep restriction dose will be defined as 10 hours - average total sleep time on study nights 10-14.
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 2 Sep 2025.
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Morning bright light in people with Chronobiology and Light, run by Rush University Medical Center at 1 site in United States.
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 3 inclusion and 14 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 2 Sep 2025. 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 United States. 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?
Dim Light Melatonin Onset (DLMO) phase shift (time frame: Change in DLMO phase from baseline (before experimental manipulation on days 9) to final phase assessment (after experimental manipulation on day 15)). The study lists 2 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 2 Sep 2025.