Teen Sleep and Light Study

August 25, 2025 updated by: Rush University Medical Center

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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 Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
88

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Illinois
      • Chicago, Illinois, United States, 60612
        • Rush University Medical Center, Biological Rhythms Research Laboratory

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

14 years to 17 years (Child)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • 14-17 years old;
  • Participants and parents have sufficient knowledge of the English language;
  • Participants are fully vaccinated for COVID-19

Exclusion Criteria:

  • 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;
  • 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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: 0 hours of sleep restriction
Bedtime will be the same as baseline.
Behavioral: Morning bright light
All participants will receive phase advancing morning bright light.
Experimental: 1.5 hours of sleep restriction
Bedtime will be 1.5 hours later than baseline.
Behavioral: Morning bright light
All participants will receive phase advancing morning bright light.
Experimental: 3 hours of sleep restriction
Bedtime will be 3 hours later than baseline.
Behavioral: Morning bright light
All participants will receive phase advancing morning bright light.
Experimental: 4.5 hours of sleep restriction
Bedtime will be 4.5 hours later than baseline.
Behavioral: Morning bright light
All participants will receive phase advancing morning bright light.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
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.
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
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.
During the experimental manipulation (study nights 10-14)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Rush University Medical Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 14, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 15, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 15, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 27, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 9, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 10, 2021

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 2, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 25, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • R01HL146772 (U.S. NIH Grant/Contract)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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