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
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.
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.
Next will be a visit where participants will spend 66 hours (2.75 days) in the laboratory.
Finally, there will be a visit where participants will spend 48 hours (2 days) in the laboratory.
135 studies on the registry are indexed under Sleep Disorders, Circadian Rhythm; 25 are open to participants now.
This study's planned enrollment of 66 is above the median of 59 across 102 interventional studies indexed under Sleep Disorders, Circadian Rhythm.
Browse Sleep Disorders, Circadian Rhythm studies →University of Colorado, Boulder is the lead sponsor of 88 studies on the registry; 20 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Circadian rhythms and light sensitivity
Behavioral: Circadian rhythm assessment · Behavioral: Light sensitivity 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.
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.
Core body temperature
Body temperature measured with a pill
Time frame: Continuously for 1. up to 39 and 2. 23 hours
Glucose
Blood sugar levels
Time frame: Continuously for 1. up to 39 and 2. 23 hours
Subjective sleepiness
Self reported sleepiness
Time frame: Every 2 hours
Psychomotor vigilance
Attention/Vigilance performance
Time frame: Every 2 hours
Skin temperature
skin body temperature
Time frame: Continuously for 1. up to 39 and 2. 23 hours
Melatonin
Melatonin levels in saliva
Time frame: Hourly for 1. up to 39 hours and 2. every 20 minutes
Started Apr 2024 (actual). Primary completion is estimated for Jul 2028, 51 months after the start.
Of 39 non-industry interventional studies with no phase under Sleep Disorders, Circadian Rhythm, half reached primary completion within 28 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 51. This study's planned 51 months is above that.
Counting every sponsor, half of 42 studies reached it within 28 months; a quarter within 8 and three quarters within 46.
How these figures are worked out, and which studies are left out of them.
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Sleep Disorders, Circadian Rhythm →
University of Colorado, Boulder