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Post COVID-19 ConditionNCT05677932

Bright Light Therapy for Post-COVID-19 Fatigue

A study testing Bright light therapy and Dim red light therapy in people with Post COVID-19 Condition, run by Chinese University of Hong Kong at 1 site in Hong Kong.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This is a randomized placebo-controlled trial to examine the efficacy of two-week bright light therapy for patients with post-COVID-19 fatigue. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Post COVID-19 Condition
What is being tested?
Bright light therapy and Dim red light therapy
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
12 participants
Where
1 siteHong Kong
Study dates
15 Feb 2023to 30 Apr 2024
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age 18 or above
  • Capable to give informed consent
  • COVID-19 infection confirmed by PCR test or a Rapid Antigen Test (RAT) with onset of at least three months
  • Reports new onset or exacerbation of fatigue after onset of COVID-19 and lasted for over two months
  • Scoring 7 or above for the item "worst level of fatigue during the last 24 hours" in the Brief Fatigue Inventory

Who cannot join

  • A current or past history of bipolar disorder, schizophrenia, neurodevelopmental disorder, organic mental disorder; intellectual disabilities or substance use disorder.
  • Presence of contraindications to bright light therapy: for example, history of light induced migraine/ epilepsy; current use of photosensitizing medications; presence of eye disease: e.g. retinal blindness, severe cataract, glaucoma.
  • Significant medical condition/ hearing impairment/ speech deficit leading to incapability of completing clinical interview.
  • Regular shift-workers
  • Trans-meridian flight in the past 3 months and during the study
  • Currently receiving any structured psychotherapy
  • Self-reported untreated sleep disorders (e.g. severe insomnia, obstructive sleep apnea, restless leg syndrome), psychiatric illness (e.g. depression), or medical conditions associated with fatigue (e.g. anemia, heart failure, autoimmune disorders)
  • Enrolment in another clinical trial of an investigational medicinal product or device.

Trial locations and contacts

1 site in 1 country.

Hong Kong1 site
  • The Chinese University of Hong Kong

    Hong Kong

Other trials in Hong Kong

About this study

This is a randomized placebo-controlled trial to examine the efficacy of two-week bright light therapy for patients with post-COVID-19 fatigue.

Read the detailed description

This randomized placebo-controlled trial aims to evaluate the efficacy of BLT in reducing fatigue symptoms after COVID-19 infection. The second aim of the study is to explore the effects of BLT on insomnia, depression and anxiety symptoms.

Method: Each eligible participant will be randomized to either i) bright light therapy (BLT) or ii) dim red light (placebo) treatment for 30-minutes daily at their habitual wake time for a total of two weeks. Participants will be evaluated at baseline, 2nd (end of treatment), and 4th week (post-treatment 2-week) for fatigue and other symptoms.

Being tested
Bright light therapy, Dim red light therapy
Keywords
COVID-19, Long COVID, Fatigue
Medical subject headings
COVID-19, Post-Acute COVID-19 Syndrome, Fatigue

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Bright light therapyDevice

    Exposure to bright light therapy for 30mins a day for two weeks

  • Dim red light therapyDevice

    Exposure to 50lux dim red light therapy for 30mins a day for two weeks

Study groups in NCT05677932
Study groupRoleWhat they receive
Bright light therapyExperimental10,000lux bright light
Receives: Device: Bright light therapy
Placebo groupExperimental50 lux dim red light
Receives: Device: Dim red light therapy

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change of fatigue symptoms

    Change in the score of the Brief Fatigue Inventory (BFI). BFI ranges from 0 to 90, higher scales indicates more severe fatigue

    Measured: at 2 weeks (at the end of treatment)

Secondary outcomes (3)
  1. Change of insomnia symptoms

    The change in the score of Insomnia Severity Index (ISI), which ranges from 0-28, higher score indicates higher severity of insomnia

    Measured: at 2 weeks (at the end of treatment)

  2. Change of depressive symptoms

    The change in the score of Patient Health Questionnaire -9 item (PHQ-9), which ranges from 0-27, with higher score indicates greater severity of depressive symptoms

    Measured: at 2 weeks (at the end of treatment)

  3. Change of anxiety symptoms

    The change in the score of Generalized Anxiety Disorder 7-item (GAD-7), which ranges from 0-21, with higher score indicates greater severity of anxiety symptoms

    Measured: at 2 weeks (at the end of treatment)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted10 Jan 2023
  2. Study start15 Feb 2023
  3. Primary completion28 Feb 2024
  4. Study completion30 Apr 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Randomized placebo-controlled trial
Masking
Single blind
Who is masked
Participant
Enrolment
12 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05677932
Sponsor's protocol ID
2022.359
Status last verified
Mar 2023
First submitted
6 Jan 2023
Last updated
20 Mar 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Bright light therapy and Dim red light therapy in people with Post COVID-19 Condition, run by Chinese University of Hong Kong at 1 site in Hong Kong.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 20 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change of fatigue symptoms (time frame: at 2 weeks (at the end of treatment)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Mar 2026.

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