DepressionNCT07599124

Effectiveness of Light Therapy Across Seasons

An observational study of Depression and Unipolar Depression, run by Geestelijke Gezondheidszorg Eindhoven (GGzE) at 1 site in Netherlands.

Completed

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

Official record

Search all trials

Trial summary

Who is it for?: Ages 18 years and older
Conditions the study is for: Depression, Unipolar Depression, Bipolar Depression Depressed Phase
What is being tested?: Bright Light Therapy
Type of treatment: Medical device
How many people: 212 participants
Where: 1 siteNetherlands
Study dates: 1 Jan 2021to 23 Dec 2022
Phase: Observational
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

Study population: The study population consists of patients with depression who are referred for treatment of depressive symptoms within a mental health care setting (GGzE, Eindhoven, The Netherlands), where bright light therapy is offered in a structured "Light Café" environment as part of routine clinical care.

Who may be able to join

Adults aged 18 years or older
Diagnosis of a depressive disorder (unipolar or bipolar), including both seasonal and non-seasonal depression
Currently indicated for bright light therapy
QIDS-SR score ≥ 6 at baseline
Able to provide informed consent
Sufficient proficiency in Dutch or English to complete questionnaires

Who cannot join

Current (hypo)manic or mixed episode
Current psychotic episode
Severe suicidal ideation requiring immediate intervention
Diagnosis of dementia
QIDS-SR score ≤ 5 at baseline
Age < 18 years

Show all 20Show fewer

Inability to provide informed consent
Insufficient language proficiency to complete study questionnaires
Initiation, dose change, or switch of antidepressant medication within 3 weeks before or during light therapy
Long-term use of agomelatine
Relative Contraindications (require consultation with treating physician before participation):
Pregnancy (first trimester)
Diabetes or other systemic vascular diseases
Eye conditions associated with increased light sensitivity
Epilepsy
Medication-Related Considerations:
Participants are advised not to start antibiotics during light therapy (existing courses should be completed prior to participation)
Participants are advised to discontinue use of photosensitizing medications or topical agents during treatment
Participants are asked to discontinue melatonin use during light therapy
A wash-out period of 1 month is required after discontinuation of melatonin or short-term agomelatine use before starting light therapy

Trial locations and contacts

1 site in 1 country.

Netherlands1 site

GGzE
Eindhoven, 5626ND

Other trials in Netherlands

About this study

Official title: Is the Antidepressant Effect of Light Therapy for People With a Depressive Disorder Comparable in the Spring/Summer vs Autumn/Winter?

This study investigates whether the antidepressant effects of bright light therapy (BLT) differ between the spring/summer season and the autumn/winter season in adults with depressive disorders. While BLT is an established treatment for seasonal affective disorder, increasing evidence suggests it may also be effective for non-seasonal depression. However, it remains unclear whether its effectiveness depends on seasonal variation in natural daylight exposure.

In this prospective study conducted in a routine clinical care setting, patients referred for depressive symptoms and a score of > 6 on the Quick Inventory of Depressive Symptomatology-Self-Report (QIDS-SR) receive BLT in a structured "Light Café" environment. Participants undergo daily morning light therapy sessions (30 minutes at 10,000 lux) for at least one week, with possible extension up to three weeks based on treatment response. A delayed-start design is used, where a subset of participants begins treatment two weeks later, allowing comparison with the natural course of depressive symptoms.

Depressive symptoms are assessed using the QIDS-SR at baseline, during treatment, and at follow-up (6 weeks and 3 months post-treatment). Sleep quality, chronotype, circadian timing, and side effects are also measured.

The primary objective is to compare the effectiveness of BLT across seasons. Secondary objectives include evaluating the persistence of treatment effects, assessing the change in sleep quality and day-to-day sleep-wake pattern, and exploring whether outcomes vary by chronotype, circadian phase, and patient characteristics.

This study aims to inform whether BLT should be considered a year-round treatment option for depressive disorders and to better understand factors influencing individual treatment response.

Conditions: Depression, Unipolar Depression, Bipolar Depression Depressed Phase
Being tested: Bright Light Therapy
Keywords: Depression, Bright Light Therapy, Chronotherapy, Sleep
Medical subject headings: Depression, Depressive Disorder

What participants receive

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

Bright Light TherapyDevice
Bright Light Therapy (BLT) will be administered according to Dutch depression guidelines, using Innolux LED light lamp (3800K, 10,000 lux). BLT will be given for one work week (Mon-Fri), 7:30-10:30 AM, 30 mins/session. Patients can have breakfast, read, or use devices. Treatment effectiveness will be evaluated using Self-Rated Quick Inventory of Depressive Symptoms (QIDS-SR). If remission is achieved (QIDS-SR < 6), no additional treatment is given. If response is insufficient (QIDS-SR ≥ 6), 5 more sessions will be added in the following week, with maximum two extensions (1-3 weeks total).

Study groups in NCT07599124
Study group	Role	What they receive
Spring/summer		Patients with a depression who received bright light therapy as part of routine clinical care. For the purpose of the analyses, participants were categorized based on the season of treatment initiation, with this cohort including those who started treatment during the spring and summer seasons. Receives: Device: Bright Light Therapy
Autumn/winter		Patients with a depression who received bright light therapy as part of routine clinical care. For the purpose of the analyses, participants were categorized based on the season of treatment initiation, with this cohort including those who started treatment during the autumn and winter seasons. Receives: Device: Bright Light Therapy

What is being measured

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

Change in depressive symptom severity (QIDS-SR)
Depressive symptom severity is assessed using the Quick Inventory of Depressive Symptomatology - Self-Report (QIDS-SR), a validated 16-item questionnaire with total scores ranging from 0 to 27 (higher scores indicating greater symptom severity). The primary outcome is the change in QIDS-SR score from baseline (pre-treatment) to end of light therapy. The analysis compares changes between participants treated in the spring/summer season and those treated in the autumn/winter season, while accounting for the delayed-start control condition.
Measured: Baseline to end of treatment (approximately 1-3 weeks after initiation of light therapy)

Secondary outcomes (5)

Sustained change in depressive symptoms (QIDS-SR follow-up)
Depressive symptom severity is assessed using the Quick Inventory of Depressive Symptomatology - Self-Report (QIDS-SR), a validated 16-item questionnaire with total scores ranging from 0 to 27 (higher scores indicating greater symptom severity). This secondary outcome evaluates the persistence of treatment effects by comparing post-treatment scores to follow-up scores.
Measured: End of treatment to 6 weeks and 3 months post-treatment
Change in sleep quality (PSQI)
Sleep quality is measured using the Pittsburgh Sleep Quality Index (PSQI), a validated self-report questionnaire with total scores ranging from 0 to 21 (higher scores indicating poorer sleep quality). The outcome reflects change in sleep quality following light therapy.
Measured: Baseline to 6 weeks and 3 months post-treatment
Chronotype (MEQ)
Chronotype is assessed using the Morningness-Eveningness Questionnaire (MEQ). This outcome examines whether baseline chronotype moderates changes in depressive symptom severity following light therapy.
Measured: Baseline (chronotype assessment), end of treatment (1-3 weeks after initiation of light therapy), 6 weeks post-treatment, and 3 months post-treatment
Adverse Events and Side Effects
Side effects are assessed using a self-report questionnaire capturing the presence and severity of common light therapy-related symptoms (e.g., headache, eye irritation, sleep disturbances).
Measured: At the end of each treatment week, up to 3 weeks
Change in Sleep-Wake Pattern during treatment
Sleep timing, duration, quality and fragmentation, are assessed using a shortened sleep diary based on the Consensus Sleep Diary. This outcome evaluates changes in sleep patterns during light therapy and their relation to treatment response. Participants completed the diaries in the clinic on Mondays and Fridays, reporting retrospectively on their sleep during the preceding nights (i.e., Friday-Sunday nights for Monday entries and Monday-Thursday nights for Friday entries).
Measured: Twice weekly during treatment, up to 3 weeks

Timeline

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

1 Jan 202123 Dec 2022

First posted20 May 2026
Study start1 Jan 2021
Primary completion7 Oct 2022
Study completion23 Dec 2022

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Other trials for DepressionStudies of the same condition, open and under way.
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: Observational
Observational model: Cohort
Time perspective: Retrospective
Enrolment: 212 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT07599124
Sponsor's protocol ID: ILB/2020038
Status last verified: May 2026
First submitted: 12 May 2026
Last updated: 20 May 2026
Results posted: No
Data monitoring committee: No
Individual data sharing: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

Recruiting
Regulated Stimulation for Optimized Network Activity and Therapeutic Equilibrium
Major Depressive Disorder
Recruiting
Metacognitive Bibliotherapy for Anxiety, Depression, and Metacognitions in University Students
Anxiety, Depression
Enrolling by invitation
Vagus Nerve Stimulation (VNS) Electroencephalogram (EEG) Protocol Supplement
Treatment Resistant Depression
Active, not recruiting
NYUCI-ES: Psychosocial Intervention to Improve Health Outcomes for Chinese and Korean ADRD Caregivers
Dementia Caregivers, Diabetes
Enrolling by invitation
Intervention to Reduce HIV Related Stigma Among Pregnant and Postpartum Women
HIV, HIV - Human Immunodeficiency Virus

All Depression trials

Study at a glance

From the registry record, last updated by the sponsor on 20 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Is the Antidepressant Effect of Light Therapy for People With a Depressive Disorder Comparable in the Spring/Summer vs Autumn/Winter?
ClinicalTrials.gov ID: NCT07599124
Acronym / sponsor ID: ILB/2020038
Conditions: Depression, Unipolar Depression, Bipolar Depression Depressed Phase
Keywords: Depression, Bright Light Therapy, Chronotherapy, Sleep
Study type: Observational
Recruitment status: Completed
Enrolment: 212 participants (actual)
Lead sponsor: Geestelijke Gezondheidszorg Eindhoven (GGzE)University, hospital or other
Study start: 1 Jan 2021 (actual)
Primary completion: 7 Oct 2022 (actual)
Study completion: 23 Dec 2022 (actual)
First posted: 20 May 2026 (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 study aims to inform whether BLT should be considered a year-round treatment option for depressive disorders and to better understand factors influencing individual treatment response.

Study design

Observational model: Cohort
Time perspective: Retrospective
Number of arms: 2

Arm	Type	Receives
Spring/summer	–	Device: Bright Light TherapyPatients with a depression who received bright light therapy as part of routine clinical care. For the purpose of the analyses, participants were categorized based on the season of treatment initiation, with this cohort including those who started treatment during the spring and summer seasons.
Autumn/winter	–	Device: Bright Light TherapyPatients with a depression who received bright light therapy as part of routine clinical care. For the purpose of the analyses, participants were categorized based on the season of treatment initiation, with this cohort including those who started treatment during the autumn and winter seasons.

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult
Study population: The study population consists of patients with depression who are referred for treatment of depressive symptoms within a mental health care setting (GGzE, Eindhoven, The Netherlands), where bright light therapy is offered in a structured "Light Café" environment as part of routine clinical care.

Key inclusion criteria (6 listed)

Adults aged 18 years or older
Diagnosis of a depressive disorder (unipolar or bipolar), including both seasonal and non-seasonal depression
Currently indicated for bright light therapy
QIDS-SR score ≥ 6 at baseline
Able to provide informed consent

Key exclusion criteria (20 listed)

Current (hypo)manic or mixed episode
Current psychotic episode
Severe suicidal ideation requiring immediate intervention
Diagnosis of dementia
QIDS-SR score ≤ 5 at baseline

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 TherapyBright Light Therapy (BLT) will be administered according to Dutch depression guidelines, using Innolux LED light lamp (3800K, 10,000 lux). BLT will be given for one work week (Mon-Fri), 7:30-10:30 AM, 30 mins/session. Patients can have breakfast, read, or use devices. Treatment effectiveness will be evaluated using Self-Rated Quick Inventory of Depressive Symptoms (QIDS-SR). If remission is achieved (QIDS-SR < 6), no additional treatment is given. If response is insufficient (QIDS-SR ≥ 6), 5 more sessions will be added in the following week, with maximum two extensions (1-3 weeks total).	Device	Autumn/winter, Spring/summer

Primary outcome

Change in depressive symptom severity (QIDS-SR)
Time frame: Baseline to end of treatment (approximately 1-3 weeks after initiation of light therapy)
Depressive symptom severity is assessed using the Quick Inventory of Depressive Symptomatology - Self-Report (QIDS-SR), a validated 16-item questionnaire with total scores ranging from 0 to 27 (higher scores indicating greater symptom severity). The primary outcome is the change in QIDS-SR score from baseline (pre-treatment) to end of light therapy. The analysis compares changes between participants treated in the spring/summer season and those treated in the autumn/winter season, while accounting for the delayed-start control condition.

5 secondary outcomes

Sustained change in depressive symptoms (QIDS-SR follow-up)
Time frame: End of treatment to 6 weeks and 3 months post-treatment
Change in sleep quality (PSQI)
Time frame: Baseline to 6 weeks and 3 months post-treatment
Chronotype (MEQ)
Time frame: Baseline (chronotype assessment), end of treatment (1-3 weeks after initiation of light therapy), 6 weeks post-treatment, and 3 months post-treatment
Adverse Events and Side Effects
Time frame: At the end of each treatment week, up to 3 weeks
Change in Sleep-Wake Pattern during treatment
Time frame: Twice weekly during treatment, up to 3 weeks

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 May 2026.
Individual participant dataSharing planned: No

Related trials for Depression

Recruiting
Regulated Stimulation for Optimized Network Activity and Therapeutic Equilibrium
Major Depressive Disorder
Recruiting
Metacognitive Bibliotherapy for Anxiety, Depression, and Metacognitions in University Students
Anxiety, Depression
Enrolling by invitation
Vagus Nerve Stimulation (VNS) Electroencephalogram (EEG) Protocol Supplement
Treatment Resistant Depression
Active, not recruiting
NYUCI-ES: Psychosocial Intervention to Improve Health Outcomes for Chinese and Korean ADRD Caregivers
Dementia Caregivers, Diabetes
Enrolling by invitation
Intervention to Reduce HIV Related Stigma Among Pregnant and Postpartum Women
HIV, HIV - Human Immunodeficiency Virus

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?

An observational study of Depression and Unipolar Depression, run by Geestelijke Gezondheidszorg Eindhoven (GGzE) at 1 site in Netherlands.

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 6 inclusion and 20 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 May 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 Netherlands. 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 in depressive symptom severity (QIDS-SR) (time frame: Baseline to end of treatment (approximately 1-3 weeks after initiation of light therapy)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07599124.

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 May 2026.