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RecruitingNCT06471374Updated Jun 17, 2026

Pathophysiology of Circadian Rhythm Delayed Sleep Wake Phase Disorder

An interventional study of Circadian rhythm assessment and Light sensitivity assessment in Delayed Sleep Phase Syndrome and Delayed Sleep Phase, sponsored by University of Colorado, Boulder. Recruiting at 2 sites in United States. Open to participants aged 16 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-17.

Sponsored by University of Colorado, Boulder · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
66
Allocation
Not applicable
Ages
16 Years to 40 Years
Sex
All
01

Study summary

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.

Read the detailed description
  • The research parts of the study are 6.5 weeks long and the study, including screening visits, involves 6 in-person visits to the Boulder campus.

  • If participants qualify for the study and choose to participate, there will be two visits where participants will pick up research equipment to wear at home for 1-2 weeks of ambulatory monitoring before being studied in the laboratory. The first ambulatory monitoring session is for 2 weeks and the second is one week.

    • On the first ambulatory monitoring session the investigators will have participants answer questions about participant's mood and cognition.
    • On both ambulatory monitoring sessions, the investigators will also ask participants to wear a blood sugar monitor and track the timing of when participants eat using a phone app. The investigators will also have participants wear a wrist worn sleep and light monitor plus a daily sleep log and Google form of when participants go to bed and wake up.

  • Next will be a visit where participants will spend 66 hours (2.75 days) in the laboratory.

    • While living in the lab, participants will not be aware of the time of day (e.g., no clocks, internet, cell phones), and the investigators will schedule participant's activities.
    • The investigators will ask participants to remain seated in bed and awake for up to \~39 hours, with the head of the bed raised. Participants will be studied under dim light similar to candlelight.
    • The investigators will frequently take saliva samples for more than 24 hours when the investigators will ask participants to stay awake. The investigators will also take four blood samples.
    • The investigators will also ask participants to perform reaction time tests, tests of participant's ability to think, and to complete ratings of how participants feel multiple times each day that participants are in the lab.
    • The investigators will also record participant's brain wave activity, muscle activity, eye movements, and heart rate when participants stay awake and during \~9h sleep opportunities.
  • The investigators will then ask participants to sleep normally at home for \~2 weeks, followed by 1 week of ambulatory monitoring.

  • Finally, there will be a visit where participants will spend 48 hours (2 days) in the laboratory.

    • While living in the lab, participants will not be aware of the time of day (e.g., no clocks, internet, cell phones) and the investigators will schedule participant's activities.
    • The investigators will expose participants to different light levels (dim light similar to candlelight and typical room light).
    • The investigators will frequently take saliva samples.
    • The investigators will also ask participants to perform reaction time tests, tests of participant's ability to think, and to complete ratings of how participants feel multiple times each day that participants are in the lab.
    • The investigators will also record participant's brain wave activity, muscle activity, eye movements, and heart rate when participants are awake and while participants sleep.
02

Conditions studied

  • Delayed Sleep Phase Syndrome
  • Delayed Sleep Phase
03

Who can participate

Ages eligible
16 Years to 40 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Delayed sleep wake phase disorder diagnosis
  • Altitude history: currently residing at Denver altitude or higher
  • BMI normal to moderately overweight

Exclusion criteria

Exclusion Criteria:

  • Recent medical condition
  • Psychiatric disorder
  • Sleep disorder
  • Medication use
04

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
66 participants (estimated)

Study arms

  • Experimental
    Assessment

    Circadian rhythms and light sensitivity

    Behavioral: Circadian rhythm assessment · Behavioral: Light sensitivity assessment

Interventions

  • BehavioralCircadian 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.

  • BehavioralLight 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.

05

What researchers measure

Primary outcomes

  1. Core body temperature

    Body temperature measured with a pill

    Time frame: Continuously for 1. up to 39 and 2. 23 hours

  2. Glucose

    Blood sugar levels

    Time frame: Continuously for 1. up to 39 and 2. 23 hours

  3. Subjective sleepiness

    Self reported sleepiness

    Time frame: Every 2 hours

  4. Psychomotor vigilance

    Attention/Vigilance performance

    Time frame: Every 2 hours

Secondary outcomes

  1. Skin temperature

    skin body temperature

    Time frame: Continuously for 1. up to 39 and 2. 23 hours

  2. Melatonin

    Melatonin levels in saliva

    Time frame: Hourly for 1. up to 39 hours and 2. every 20 minutes

06

Study locations

2 of 2 sites recruiting
  • University of Colorado
    Boulder, Colorado 80303, United States
    Recruiting
  • Northwestern University
    Chicago, Illinois 60611, United States
    • Phyllis Zee, MD, PhD · Contact · (312) 695-7950
    • Phyllis Zee, MD, PhD · Principal investigator
    • Kathryn Reid, PhD · Sub investigator
    Recruiting
07

Registry details

Key details

Study ID
NCT06471374
Lead sponsor
University of Colorado, Boulder
Collaborators
Northwestern University, National Heart, Lung, and Blood Institute (NHLBI)
Responsible party
Kenneth Wright (Professor, University of Colorado, Boulder) — Principal investigator
First posted
Jun 24, 2024
Start date
Apr 2, 2024
Primary completion
Jul 2028 (estimated)
Completion
Jul 2028 (estimated)
Last update
Jun 17, 2026

Study contacts

Kenneth Wright, PhD
Contact
sleep.study@colorado.edu
303-735-1923
Kenneth Wright, PhD
principal investigator · University of Colorado, Boulder

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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