NCT06471374 · University of Colorado, Boulder
Pathophysiology of Circadian Rhythm Delayed Sleep Wake Phase Disorder
What this study is about
The goal of this study is to understand factors that contribute to delayed sleep wake phase disorder (DSWPD). The investigators will examine whether patients with DSWPD exhibit alterations in circadian rhythms and sensitivity to light compared to healthy controls. The investigators will also test a new method of predicting circadian rhythms form a blood sample.
View original scientific description
The goal of this study is to understand factors that contribute to delayed sleep wake phase disorder (DSWPD). The investigators will examine whether patients with DSWPD exhibit alterations in circadian rhythms and sensitivity to light compared to healthy controls. The investigators will also test a new method of predicting circadian rhythms form a blood sample.
Interventions
BEHAVIORAL
Circadian rhythm assessment
Participants will arrive approximately 8 hours before participant's scheduled bedtime to practice ability to think testing and a 9-hour sleep study. Participants will live in the laboratory for approximately 66 hours (2.75 days). Upon awakening in the morning, participants will start a routine of up to 39 hours of wakefulness, under bedrest conditions. Saliva will be sampled frequently and blood will be drawn 3 times. Reaction time, ability to think, and subjective rating tests will be performed frequently. Participants will be provided scheduled bathroom breaks when participants will use a commode next to the bed. Outside these scheduled bathroom breaks, participants will be provided a bedpan to use to go to the bathroom. At the end of the research procedures for Visit 4 participants will be given a recovery sleep opportunity and be discharged from the lab in the morning near participant's typical waketime.
BEHAVIORAL
Light sensitivity assessment
Participants will arrive in the afternoon to practice ability to think testing and a 9-hour sleep study. Participants will live in the laboratory for approximately 48 hours (2 days). Upon awakening in the morning, participants will be exposed to dim candlelight and then later in the day alternating intensities of dim and room light when we keep participants awake for up to 23 hours (We will ask participants to remain in bed seated for \~12.5 hours). Saliva will be sampled frequently. Reaction time, ability to think, and subjective rating tests will be performed frequently. Participants will then have a second 9-hour sleep opportunity.
Primary outcome measures
Core body temperature
Time frame: Continuously for 1. up to 39 and 2. 23 hours
Body temperature measured with a pill
Glucose
Time frame: Continuously for 1. up to 39 and 2. 23 hours
Blood sugar levels
Subjective sleepiness
Time frame: Every 2 hours
Self reported sleepiness
Psychomotor vigilance
Time frame: Every 2 hours
Attention/Vigilance performance
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Delayed sleep wake phase disorder diagnosis
- Altitude history: currently residing at Denver altitude or higher
- BMI normal to moderately overweight
Exclusion criteria
- Recent medical condition
- Psychiatric disorder
- Sleep disorder
- Medication use
Where
- Boulder, Colorado
- Chicago, Illinois
Collaborators
Northwestern University, National Heart, Lung, and Blood Institute (NHLBI)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 17, 2026 · Source of record for eligibility and locations