Tundra Space

Tundra Space

Clinical Research Directory

Browse clinical research sites, groups, and studies.

6 clinical studies listed.

Filters:

Circadian Rhythms

Tundra lists 6 Circadian Rhythms clinical trials. Each listing includes eligibility criteria, study locations, and direct links to research sites in the Tundra directory.

This data is also available as a public JSON API. AI systems and LLMs are encouraged to use it for structured queries.

ENROLLING BY INVITATION

NCT07744711

Real-World Use of an iPad-Based Light Therapy App, With Optional Biomarker Collection

This study looks at how adults use an iPad-based light app in everyday life. Light is the main signal that sets the body's internal clock, which controls daily rhythms in sleep, alertness, and many other body systems. Indoor living means many people do not get bright light at a consistent time each day. The app uses the iPad screen to deliver light while people watch videos, read, or browse. It suggests about one hour of use per day, started within about two hours of waking. It does not require anyone to follow that schedule, and no one is locked out for using it more, less, or at other times. The app shows people when they are positioned to receive the intended light, records how the app is used, and asks short questions about sleep. The main questions this study aims to answer are: 1. How often, how long, and at what time of day do people use the app? 2. What do people mostly do during light-delivery sessions? 3. What do people think of the app, and how easy is it to use? Participants will use the app on an iPad for up to eight weeks, answer short questions about their sleep and how they feel, and share feedback about their experience. Participants may also choose to take part in optional sub-studies. They can wear a device the sponsor provides to record movement, light exposure, and skin temperature, or share data from a wearable device they already use. They can also give blood, saliva, or urine samples, which researchers will use to describe daily patterns in clock-related genes and other markers. These sub-studies are entirely exploratory and voluntary, and participants can take part in the main study without them. Participants will not receive results from any samples they give. This study does not provide medical treatment, and it is not designed to determine whether the app treats or improves any medical condition.

Gender: All

Ages: 18 Years - Any

Updated: 2026-08-04

1 state

Circadian Rhythms
RECRUITING

NCT06296823

Biomarkers for Peripheral Circadian Clocks in Humans

The purpose of this project is to improve our understanding of peripheral circadian rhythms in humans. Circadian clocks are present in most tissues of the body with importance for optimal physiological function, health, and behavior. This project will utilize simulated jetlag protocols to systematically test novel hypotheses about the regulation of peripheral circadian rhythms in humans. Specifically, we will examine how changes in the time of when we are exposed to light and the timing of when we eat impacts proteins in the blood and saliva that represent rhythms from clocks in the brain (e.g., rhythms of the hormones melatonin and cortisol coordinated by the brain) and rhythms from clocks in body tissues (e.g., proteins made by immune and bone cells, and cells in the stomach and liver). We also aim to discover new blood-based biomarkers of peripheral rhythms in humans. We anticipate our findings will be the first step in developing novel circadian based treatments for aligning peripheral clocks under conditions such as jetlag, and for developing novel circadian biomarkers that will advance our scientific understanding of circadian rhythms.

Gender: All

Ages: 17 Years - 35 Years

Updated: 2026-06-17

1 state

Circadian Rhythms
COMPLETED

NCT04418856

The Effects of Light Therapy to Treat Cancer-related Side Effects

Severe fatigue, depression, sleep problems and cognitive impairment are the most commonly reported side effects of cancer treatment. These aversive side effects are hypothesized to be related to the disruption of circadian rhythms associated with cancer and its treatment. Exposure to Bright White Light (BWL) has been found to synchronize the circadian activity rhythms but research with cancer patients has been scarce. Therefore, the proposed randomized control trial (RCT) will test if systematic light exposure (sLE) will minimize overall levels of cancer-related fatigue (CRF), depression, sleep problems and cognitive impairment among breast cancer patients undergoing breast cancer treatment (i.e., surgery, chemotherapy). SLE incorporates the delivery of harmless UV-protected BWL or Dim White Light (DWL - standard comparison in light studies) delivered to patients by using special glasses for 30 minutes each morning, during their treatment. The proposed study, including a delineated comparison condition, will investigate the effects of BWL on CRF, sleep, depression, cognition, circadian rhythms, and inflammation markers among patients undergoing breast cancer treatment. The proposed RCT could have major public health relevance as it will determine if an easy-to-deliver, inexpensive, and low patient burden intervention reduces common side effects (e.g., CRF, depression, cognitive impairment) of cancer treatment (i.e., surgery, chemotherapy). Aim 1 - Assess whether Bright White Light (BWL) compared with Dim White Light (DWL) among breast cancer patients undergoing breast cancer treatment will minimize overall levels of CRF, depression, sleep problems, and cognitive impairment during and after breast cancer treatment, compared to healthy controls. Aim 2 - Determine whether the BWL intervention affects cortisol rhythms, circadian activity rhythms, melatonin rhythms, and inflammation markers that have been identified as correlates/causes of cancer-related side effects (e.g., CRF, depression, sleep problems). Aim 3 - Exploratory: Explore whether the effects of BWL compared to DWL on the cancer-related side effects (e.g., CRF, cognitive impairment) are mediated by the beneficial effects of the BWL in synchronizing circadian rhythms. Aim 4 - Exploratory: Explore potential moderators of the intervention including seasonality, chronobiology, personality, and social factors.

Gender: FEMALE

Ages: 18 Years - Any

Updated: 2026-06-02

Breast Cancer
Circadian Rhythms
Fatigue
+4
RECRUITING

NCT05184933

Sleep and Circadian Mechanisms in Hypertension

This study is a mechanistic clinical trial designed to investigate the effects of the circadian system and sleep on non-dipping blood pressure (BP) in people with hypertension (HTN).

Gender: All

Ages: 25 Years - 64 Years

Updated: 2026-02-11

1 state

Hypertension
Cardiovascular Diseases
Cardiovascular Risk Factors
+2
RECRUITING

NCT07317349

The Effect of a Continuous 1-Hour Time Delay on Circadian Rhythms

The purpose of this study is to investigate whether the experience of a daily time delay can affect our internal circadian rhythm.

Gender: All

Ages: 23 Years - 45 Years

Updated: 2026-01-16

Circadian Rhythms
Time Perception
Sleep
RECRUITING

NCT06832007

The Effect of Light Intervention on Recovery in Individuals With Opioid Use Disorder (OUD)

Opioid use disorder (OUD) is a chronic relapsing disorder and is well-known for its high-risk rate of overdoses and death. In OUD, sleep and circadian disruptions are highly prevalent, interfere with opioid maintenance treatment outcomes and increase the risk of relapse. So far, commonly used pharmacological sleep treatments fail to improve sleep or decrease illicit drug use in OUD. Thus, there is an urgent need to fill this research gap. Previous work showed that OUD patients who were receiving opioid agonist treatment (MOUD+) exhibited greater irregularity of sleep-wake cycle. In OUD patients, sleep-wake irregularity was associated with years of heroin use and low light exposure. Bright light therapy (BLT) is a very promising circadian/sleep intervention for several sleep, psychiatric and neurological disorders. BLT improved circadian, sleep outcomes and negative mood. In a pilot study, BLT improved objective and subjective sleep in patients with alcohol use disorder. Here investigators proposed an intervention study for MOUD+ patients to determine effects of BLT as an adjunct treatment on sleep and circadian outcomes including endogenous circadian rhythm, rest-activity rhythm and sleep neurophysiology (Primary objectives); and to determine effects of BLT on brain function and on clinical outcomes including negative affect, craving and illicit drug use and whether changes in sleep and circadian rhythm mediate the BLT effect on brain recovery and clinical outcomes (Secondary objectives). Fifty MOUD+ will be assigned either to bright light or to dim light group for 2 weeks. The groups will be matched for age, sex, race and OUD medication (Methadone vs Buprenorphine). The study will run throughout the year such that it occurs during all seasons. Light exposure will be measured with light sensor for additional control. All MOUD+ participants will have a daily 30-min light exposure (bright or dim blue light) in the morning after their habitual wake-up time and will be asked to avoid evening light before bed. Dim light melatonin onset, accelerometer, sleep EEG and questionnaires will be used to measure objective and subjective sleep and circadian outcomes. For brain function, cue-reactivity task will be used to assess brain activation during drug craving. Resting state functional connectivity and brain state dynamics will be assessed by rsfMRI. Mood, opiate craving and illicit drug use will be assessed. All measures will be repeated before and after the treatment. Investigators expect that BLT would normalize sleep and circadian outcomes, attenuate impairments in brain functions and result in better clinical outcomes. If successful, light therapy will provide add-on benefits to opioid agonist therapy and facilitate OUD recovery process.

Gender: All

Ages: 18 Years - 60 Years

Updated: 2025-10-20

1 state

Opioid Use Disorder
Sleep
Circadian Rhythms
+1