ETD

• blood-based biomarkers
• cognitive decline
• mbi
• mci
• nfL
• pTau217

Recent clinical evidence strongly supports the idea that late onset psychiatric symptoms should be considered as early indicators of underlying neurodegenerative processes. Mild Behavioral Impairment (MBI) has been defined as a distinct clinical syndrome that characterizes the emergence of persistent neuropsychiatric symptoms (NPS) in later life, not better explained by primary psychiatric disorders, and potentially preceding cognitive decline. MBI is characterized by NPS lasting at least six months, representing a noticeable change from baseline behavior, observable by informants, and associated with functional impairment in social, interpersonal, or occupational domains. Blood-based biomarkers, such as phosphorylated tau at threonine 217 (pTau217) and neurofilament light chain (NfL), have recently emerged as promising, accessible, and cost-effective tools for the early detection of neurodegenerative processes. These biomarkers can be measured through minimally invasive procedures, offering significant advantages over more traditional methods such as cerebrospinal fluid analysis or positron emission tomography (PET), which are often expensive, less available, and less tolerated by patients. pTau217 has shown high specificity for Alzheimer’s disease pathology, correlating strongly with amyloid-β and tau PET imaging, as well as with cognitive decline trajectories. NfL, on the other hand, reflects axonal damage and is considered a more general marker of neurodegeneration, with elevated levels observed in several neurodegenerative disorders.