MAPT and Alzheimer disease: Potential biomarkers include neuroimaging techniques (e.g., PET, fMRI) to detect structural and functional changes, molecular biomarkers from blood or cerebrospinal fluid (CSF) markers, such as inflammatory markers, tau protein, and amyloid beta, as well as genetic markers like serotonin and dopamine polymorphisms, especially in relation to the manifestation and prognosis of NPS in AD.