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Study identifier: NCT06949644 Synced from ClinicalTrials.gov · July 28, 2026
● Recruiting

Pupillometry in Delayed Sleep Wake Phase Disorder

Condition: Delayed Sleep-Wake Phase Disorder  ·  Sponsor: Northwestern University

PhaseNA
Planned participants220
Who can joinAll sexes, 16 Years to no upper limit
Healthy volunteersNo

About this study

The goal of this observational study is to characterize the pupil light response in patients with delayed sleep-wake phase disorder. A subset of participants will take part in a clinical trial to determine if increasing serotonin can alter the circadian response to light. The main questions it aims to answer is: Are there differences in the light response in patients with delayed sleep-wake phase disorder? Does citalopram increase melatonin suppression in patients with delayed sleep-wake phase disorder? Participants will complete activity and melatonin testing at home to determine their circadian timing. This will be followed by an eye test looking at the pupil response to different light stimuli. A subset of participants will complete two inpatient admissions where melatonin levels will be sampled and they will be exposed to a bright light. During one round of testing they will receive a placebo and in the other round of testing they will take a single dose of citalopram, a selective serotonin reuptake inhibitor.

This description comes directly from the study's public registry record.

Talk to the study team

Sabra Abbott, MD, PhD  ·  312-695-7950  ·  sabra.abbott@northwestern.edu

Always discuss trial participation with your own doctor first.

Locations (1)

Northwestern UniversityChicago, Illinois, United StatesRecruiting

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Source record: clinicaltrials.gov/study/NCT06949644