Home-based transcranial photobiomodulation improves cognitive function in mild cognitive impairment due to Alzheimer's disease: A randomized, double-blind, placebo-controlled confirmatory trial

BackgroundAlzheimer's disease (AD) is a progressive neurodegenerative disorder in which early bioenergetic dysfunction is increasingly implicated in its pathogenesis. Transcranial photobiomodulation (tPBM), a non-invasive neuromodulation using near-infrared light, has shown promise in improving cerebral metabolism and cognitive function.ObjectiveTo assess the safety and efficacy of a home-administered tPBM intervention in individuals with mild cognitive impairment (MCI) due to AD.MethodsIn this randomized clinical trial, 80 participants meeting the NIA-AA criteria for MCI due to AD were recruited. Participants self-administered a tPBM device emitting 808 nm near-infrared light over the bilateral dorsolateral prefrontal cortex, six times weekly for 12 weeks. The primary outcome was the change in MoCA-K score from baseline to week 13. Secondary outcomes included K-MMSE2, CERAD-K, and GDepS scores.ResultsActive tPBM significantly improved cognitive performance compared with the placebo. Mean MoCA-K scores increased by 3.87 ± 2.51 points in the active group versus a 0.74 ± 2.85 point decline in the placebo group (p < 0.001). K-MMSE2 scores improved significantly (p < 0.001). CERAD-K showed a significant between-group difference at week 13 (p < 0.001), while GDepS scores remained unchanged. No device-related adverse events occurred, and adherence to home-based treatment was high.Conclusions12 weeks of home-administered tPBM safely and significantly improved cognitive function in individuals with MCI due to AD. The observed benefits are consistent with enhanced mitochondrial metabolism, cerebral perfusion, and synaptic efficiency. These findings support tPBM as a promising, non-pharmacological treatment for MCI due to AD and as a preventative strategy against AD.Trial RegistrationKorean Clinical Research Information Service (CRiS), https://cris.nih.go.kr, KCT0011155.