Efficacy of Bright Light Therapy on Cognitive Impairment in Major Depressive Disorder and Its Neuroimaging Mechanisms: Protocol for a Randomised Controlled Trial

NCT07508215 | Recruiting

• 1 other identifier: 7262156
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 2

Brief Summary

This study aims to validate the therapeutic efficacy and safety of bright light therapy (BLT) in ameliorating cognitive impairment (CI) in major depressive disorder (MDD), characterize the functional and structural features of the hippocampus (HPC)-dorsolateral prefrontal cortex (dlPFC) neural circuitry in MDD participants with CI and examine the mediating effect of the HPC-dlPFC neural circuit on CI induced by BLT treatment in MDD participants. MDD participants will be required to only receive selective serotonin reuptake inhibitors (SSRIs) as monotherapy for at least four weeks, or medication-free status before enrollment. Eligible participants will be randomly assigned to the experimental group and the control group. The experimental group will receive the intervention of BLT, and the control group will receive the intervention of dim red light (DRL). The intervention will last for four weeks, 6 days per week, with 40 minutes each day between 7 am and 10 am. The MDD participants will be followed once in the end of each week during the 4-week intervention and in the end of the 4th week after intervention. Demographic information will be collected at baseline; cognitive function will be evaluated at baseline, weeks 2, 4, and 8 after intervention beginning; and other symptoms such as depression, anxiety and sleep were assessed at baseline, weeks 1, 2, 3, 4, and 8 after intervention beginning. Moreover, structural and functional MRI scans will be made at baseline and post-intervention. During the intervention, MDD participants will be required to keep a record of daily light exposure duration and complete the daily sleep diary as well.

Conditions

Neuroimaging; Cognitive Impairment; Major Depressive Disorder (MDD); Bright Light Treatment

Keywords

Major Depressive Disorder; Neuroimaging; Magnetic Response Imaging; Bright Light Therapy; Cognitive Impairment; Randomized Controlled Trial

Outcome Measures

Primary Outcomes (1)

• Symbol Coding (SC)

  The Symbol Coding (SC) is a coding paradigm adapted from the Digit Symbol Substitution Test (DSST), both of which use essentially the same method, except in reverse; instead of drawing symbols that match digits, the SC requires to write the matching digit in the blank. The task has been included as a subtest in the Brief Assessment of Cognition in Schizophrenia; in this task, subjects are required to write numerals 1-9 as matches to nonmeaningful symbols on a response sheet for 90 s, as based on a key provided to them, with higher scores reflecting better performance.

  screen, baseline, weeks2, 4, and 8

Secondary Outcomes (15)

• Hamilton Depression Rating Scale-17（HDRS-17）

  screen, baseline, weeks1, 2, 3, 4, and 8

• The 20-item Perceived Deficits Questionnaire for Depression（PDQ-D-20）

  baseline, weeks 2, 4, and 8

• The Chinese Brief Cognitive Test（CBCT）

  baseline, weeks 2, 4, and 8

• Stroop Color-Word Test (SCWT)

  baseline, weeks 2, 4, and 8

• Hopkins Verbal Learning Test-Revised (HVLT-R)

  baseline, weeks 2, 4, and 8

Study Arms (3)

DRL control group

PLACEBO COMPARATOR

Eligible MDD participants will be randomly subjected to the DRL control group. The light source intensity will be set at \<100 lux and placed 0.6 meters away from the MDD participant. They will be required to staring at the light source for 2 seconds every 5 minutes. The DRL control group will be administered for 40 minutes each day between 7:00 AM and 10:00 AM, lasting for four weeks, 6 days per week.

Device: DRL

BLT experimental group

EXPERIMENTAL

Eligible MDD participants will be randomly subjected to the BLT experimental group. The source intensity of BLT experimental group will be set at 10000 lux and placed 0.45 meters away from the MDD participant. They will be required to staring at the light source for 2 seconds every 5 minutes. The BLT experimental group will be administered for 40 minutes each day between 7:00 AM and 10:00 AM, lasting for 4 weeks, 6 days per week.

Device: BLT

healthy control

NO INTERVENTION

Interventions

BLT DEVICE

Using a hybrid white light box with independent intellectual property rights, with an intensity of 10000lux and a main wavelength of 476.4nm

BLT experimental group

DRL DEVICE

Using a dim red light box as the placebo, with an intensity of \<100lux and a main wavelength of 690.4nm

DRL control group

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may not qualify if:

• MDD diagnosis according to the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-Ⅳ), first episode or recurrence, confirmed by an experienced psychiatrist using the Mini International Neuropsychiatric Interview.
• Age between 18 and 60 years; and gender no-limited;
• The severity of MDD symptoms must be ≥14 scores on the HAMD-17;
• With CI currently, defined as a total score of \<70 on the SC;
• A SSRI monotherapy at stable dosages for at least 4 weeks; or medication-free status;
• Education level above primary school, able to understand and cooperate in completing the study procedures;
• Voluntarily participating in this study and sign the informed consent before enrollment.
• Current or past diagnosis of any disorder other than MDD according to DSM-Ⅳ criteria;
• The scores on the Young Mania Rating Scale (YMRS) are\>8;
• The participants who have undergone other intervention in addition to SSRIs whinin the past 6 months or now, or who plan to do that in 1 month;
• The participants with strong self-blame, self-harm, or suicidal risks (the HAMD-17 suicide item score of ≥3);
• The participants with severe physical illnesses, including heart failure, renal failure, severe liver dysfunction, hyperthyroidism, or hypothyroidism; Or a history of severe brain trauma or organic brain pathology (e.g., intracerebral hemorrhage, large-area cerebral infarction, encephalitis, epilepsy), as well as neurological diseases;
• The participants with any degree of retinal pathology, including retinal dystrophy, age-related macular degeneration, diabetic retinopathy, cataracts, glaucoma, or other ocular diseases;
• The participants with photosensitive conditions, such as systemic lupus erythematosus, porphyria, chronic photodermatitis, solar urticaria, or those currently receiving medications that may increase photosensitivity (e.g., phenothiazines, antimalarials, propranolol, hypericin, stimulants, or chronic treatment with nonsteroidal anti-inflammatory drugs);
• Pregnant or lactating women;

Sponsors & Collaborators

• Peking University Sixth Hospital: lead

Study Sites (2)

Peking University Sixth Hospital

Beijing, Beijing Municipality, 100191, China

RECRUITING

Yan'an Third People's Hospital

Yanan, Shanxi, China

RECRUITING

MeSH Terms

Conditions

Depressive Disorder, Major; Cognitive Dysfunction

Condition Hierarchy (Ancestors)

Depressive Disorder; Mood Disorders; Mental Disorders; Cognition Disorders; Neurocognitive Disorders

Study Officials

• Xiaozhen Lv, Ph.D

  Peking University Sixth Hospital

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Xiaozhen Lv, Ph.D

CONTACT

+8601062723705; lxz120300@163.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Model Details: Patients will be coded according to the order of enrollment and randomly assigned to the experimental group or the control group by the random number method.

Study Record Dates

• First Submitted: March 27, 2026
• First Posted: April 2, 2026
• Study Start: April 10, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2028
• Last Updated: July 6, 2026

Record last verified: 2026-07

Locations

CN (2)