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Improved cognitive function, efficiency, saccadic eye movement, and depressive symptoms in mild cognitive impairment with transcranial photobiomodulation
Tsz‐lok Lee, Timothy C. Y. Kwok, LINDA C. W. LAM, Helene Hoi-Lam Fung, Mei‐chun Cheung, Yvonne M. Y. Han, Agnes Sui-Yin Chan. Journal of Alzheimer s Disease, 2025-07-24
Topic: Brain proteins, microglia and lab models
Background Mild cognitive impairment (MCI) is a critical stage with higher progression to Alzheimer's disease, yet effective interventions are still lacking. Objective Some empirical studies have shown that transcranial photobiomodulation (tPBM) may be effective in enhancing cognitive function. To further investigate its effectiveness, a controlled experiment was conducted. Methods In this study, 36 community-dwelling older adults with MCI were assigned to receive either real tPBM (experimental group; n = 25) and others without intervention (control group; n = 11) over three weeks. Participants underwent comprehensive assessments before and after the intervention, including neuropsychological tests, measurements of oxygenated hemoglobin (HbO) using function near-infrared spectroscopy during a visual working memory task, saccadic movement measurement using an eye-tracking device, and a questionnaire assessing depressive symptoms. Results Compared to the control group, the experimental group demonstrated significant improvements. They showed enhanced cognitive efficiency, as evidenced by improved visual working memory performance, reduced anti-saccade latency, higher scores in the Montreal Cognitive Assessment, and faster completion time in the Shape Trail Test B. In addition, significantly more participants in the experimental group showed improvement in depressive symptoms after the intervention. Conclusions These findings provide preliminary evidence that tPBM may effectively improve neuropsychological, physiological, and psychological outcomes in individuals with MCI. This trial was registered in the Chinese Clinical Trial Registry ( http://www.chictr.org.cn , registration number: ChiCTR2400090408).
Key findings
- Objective Some empirical studies have shown that transcranial photobiomodulation (tPBM) may be effective in enhancing cognitive function.
- Results Compared to the control group, the experimental group demonstrated significant improvements.
- In addition, significantly more participants in the experimental group showed improvement in depressive symptoms after the intervention.
- Conclusions These findings provide preliminary evidence that tPBM may effectively improve neuropsychological, physiological, and psychological outcomes in individuals with MCI.
Why it matters
In 36 older adults with mild cognitive impairment, those receiving transcranial photobiomodulation showed improved cognitive efficiency, eye movement measures and depressive symptoms compared with controls. The authors describe this as preliminary evidence that the approach may improve these outcomes.
Study details
- Participants25
- Evidence strengthLow
How this study scored 38/100
Published in a peer-reviewed journal. Scored zero for study design, effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Journal of Alzheimer s Disease) |
| Journal's citation record | 2 / 4 | Journal of Alzheimer s Disease: journal h-index 218 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 4 / 5 | 2025 — within 3 year(s) of the newest study here |
| Sample size | 1 / 4 | 25 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 1 / 7 | Cited 2 times (OpenAlex, 2026-10-10) |
| Citations per year | 0 / 5 | 0.7 citations a year over 3 year(s) since 2025 |
| Impact for its field and year | 2 / 6 | Cited 1.1× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 0 / 4 | Cited 2 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Agnes Sui-Yin Chan: h-index 50 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Chinese University of Hong Kong: institution h-index 1,100 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 2 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 40702818) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 38 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
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Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record names 7 authors; APA and Vancouver show the first six, BibTeX and the downloads carry all of them. Check the citation against the original before you use it.
APA 7th
Lee, T., Kwok, T. C. Y., LINDA C. W., L. A. M., Fung, H. H.-L., Cheung, M., Han, Y. M. Y., et al. (2025). Improved cognitive function, efficiency, saccadic eye movement, and depressive symptoms in mild cognitive impairment with transcranial photobiomodulation. Journal of Alzheimer s Disease. https://doi.org/10.1177/13872877251361033
Vancouver
Lee T, Kwok TCY, LINDA C. W. LAM, Fung HH.-L, Cheung M, Han YMY, et al. Improved cognitive function, efficiency, saccadic eye movement, and depressive symptoms in mild cognitive impairment with transcranial photobiomodulation. Journal of Alzheimer s Disease. 2025. doi:10.1177/13872877251361033. PMID: 40702818.
BibTeX
@article{lee2025-40702818,
author = {Lee, Tsz‐lok and Kwok, Timothy C. Y. and LINDA C. W., L. A. M. and Fung, Helene Hoi-Lam and Cheung, Mei‐chun and Han, Yvonne M. Y. and Chan, Agnes Sui-Yin},
title = {{Improved cognitive function, efficiency, saccadic eye movement, and depressive symptoms in mild cognitive impairment with transcranial photobiomodulation}},
journal = {Journal of Alzheimer s Disease},
year = {2025},
doi = {10.1177/13872877251361033},
pmid = {40702818},
url = {https://doi.org/10.1177/13872877251361033}
}
Studies this one cites
Referenced by this study and also in the alzhub library, so you can read them here.