Alzheimer's Disease Clinical Trials

This is a prospective, observational cohort study. The primary objective is to characterize the clinical features and mechanisms of behavioral and psychological symptoms of dementia (BPSD) in patients with probable Alzheimer's disease (AD) who are plasma p-Tau217 negative, and to compare them with p-Tau217-positive patients. After grouping participants by an authoritative p-Tau217 cutoff value, the negative and positive groups will be systematically compared across all 12 domains of the Neuropsychiatric Inventory (NPI). Participants will be followed up at 6, 12, and 18 months to compare the incidence of cognitive decline, new-onset severe BPSD (hallucinations, agitation/aggression, depression, etc.), cerebrovascular events, and hospitalization between the two groups. As an exploratory objective, baseline BPSD domains combined with imaging (white matter hyperintensity burden) and blood biomarkers (NfL, IL-6, GFAP, etc.) will be used to construct a simple prognostic risk-stratification model within the negative group and to validate its predictive performance. The study aims to improve the recognition of non-AD-driven dementia with overlapping clinical presentations, thereby informing clinical management and care planning in the era of biology-based AD diagnosis.