Effects of whole-head 810 nm near-infrared therapy on cognitive and neuropsychiatric symptoms in Alzheimer's disease: A pilot study

Background Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by significant cognitive and behavioral impairments. Near-infrared (NIR) light treatment has shown potential in cognitive improvement in previous studies. However, clinical trials of NIR for AD remain limited. Objective This study investigated the safety and effects of whole-head 810 nm NIR therapy in AD patients, including long-term efficacy. Methods An open-label pilot study on whole-head NIR treatment for AD patients was conducted. Nine AD patients completed 4-month treatment (810 nm, 100 mW/cm², 30 min/session, 6 sessions weekly). Safety and efficacy were evaluated at baseline, months 2 and 4, and 2-month post-treatment. Results After four months of whole-head NIR treatment, mean changes from baseline on the Mini-Mental State Examination were 3.2 ( p = 0.02). Mean changes from baseline on the Alzheimer's Disease Assessment Scale-Cognitive were −5.0 ( p = 0.05), mean changes from baseline on the Montreal Cognitive Assessment were 1.9 ( p = 0.12). Mean changes from baseline on the Neuropsychiatric Inventory were −4.2 ( p = 0.47). These benefits were sustained two months at least. With no device-related adverse effects were reported. Conclusions Whole-head 810 nm NIR light is safe and offers promising benefits for AD patients. To fully confirm its efficacy, durability, and underlying mechanisms, further large-scale randomized controlled trials are necessary.