Photobiomodulation: multifaceted therapeutic effects on disorders in the central nervous system

Abstract Conventional pharmacological interventions for brain diseases are often limited by complex pathophysiological mechanisms, suboptimal efficacy, and pronounced side effects. In contrast, photobiomodulation (PBM) has attracted increasing attention due to its non-invasive nature, multi-target effects, and favourable safety profile. In brain diseases, PBM employs specific light wavelengths to activate mitochondrial cytochrome c oxidase and photosensitive proteins and to regulate neuronal oscillatory activity and neuroglial functions. Human studies demonstrated the efficacy of PBM in improving cognitive performance, motor symptoms, and emotional distress in patients with neurodegenerative diseases, brain trauma, and psychiatric disorders. Therapeutic outcomes are influenced by key parameters of the protocol, such as wavelength, dosage, and frequency, as well as inter-individual variability in anatomical and physiological factors. Future research needs to focus on establishing a database of disease-specific parameters to enable personalised treatment protocols by integrating imaging and molecular biomarkers and performing large-scale clinical trials to validate long-term safety and translational potential.