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.
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.
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.
- Conditions
- Post COVID-19 Condition
- 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 group | Role | What they receive |
|---|---|---|
| Bright light therapy | Experimental | 10,000lux bright light Receives: Device: Bright light therapy |
| Placebo group | Experimental | 50 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.
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)
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)
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)
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.
- First posted10 Jan 2023
- Study start15 Feb 2023
- Primary completion28 Feb 2024
- Study completion30 Apr 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Post COVID-19 ConditionStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Joey WY Chan, Chinese University of Hong Kong
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
Study at a glance
From the registry record, last updated by the sponsor on 20 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Bright Light Therapy for Post-COVID-19 Fatigue
- ClinicalTrials.gov ID
- NCT05677932
- Acronym / sponsor ID
- 2022.359
- Conditions
- Post COVID-19 Condition
- Keywords
- COVID-19, Long COVID, Fatigue
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 12 participants (actual)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- 15 Feb 2023 (actual)
- Primary completion
- 28 Feb 2024 (actual)
- Study completion
- 30 Apr 2024 (actual)
- First posted
- 10 Jan 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a randomized placebo-controlled trial to examine the efficacy of two-week bright light therapy for patients with post-COVID-19 fatigue.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- Randomized placebo-controlled trial
| Arm | Type | Receives |
|---|---|---|
| Bright light therapy | Experimental | Device: Bright light therapy10,000lux bright light |
| Placebo group | Experimental | Device: Dim red light therapy50 lux dim red light |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- 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
Key exclusion criteria (8 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Bright light therapyExposure to bright light therapy for 30mins a day for two weeks | Device | Bright light therapy |
| Dim red light therapyExposure to 50lux dim red light therapy for 30mins a day for two weeks | Device | Placebo group |
Primary outcome
Change of fatigue symptoms
Time frame: at 2 weeks (at the end of treatment)
Change in the score of the Brief Fatigue Inventory (BFI). BFI ranges from 0 to 90, higher scales indicates more severe fatigue
3 secondary outcomes
Change of insomnia symptoms
Time frame: at 2 weeks (at the end of treatment)
Change of depressive symptoms
Time frame: at 2 weeks (at the end of treatment)
Change of anxiety symptoms
Time frame: at 2 weeks (at the end of treatment)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Mar 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
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.