Early detection of dementia: Identifying biomarkers for early intervention.

Dementia is a progressive neurodegenerative syndrome marked by the deterioration of cognitive, behavioural, and functional abilities and represents a major global health challenge in aging populations. It comprises a heterogeneous group of disorders, including Alzheimer's disease, vascular dementia, frontotemporal dementia, and dementia with Lewy bodies, each defined by distinct clinical trajectories and molecular pathologies. This review integrates current understanding of dementia subtypes, disease stages, and progression patterns, emphasizing the interconnected molecular and cellular mechanisms underlying cognitive decline, such as amyloid-β deposition, Tau pathology, neuroinflammation , mitochondrial dysfunction, synaptic failure, and vascular impairment. Recent advances in biomarker discovery are highlighted, spanning genetic and epigenetic markers, blood-based and cerebrospinal fluid biomarkers, neuroimaging modalities, and emerging digital health technologies. In particular, plasma phosphorylated tau, amyloid-β ratios, neurofilament light chain, and inflammatory markers demonstrate strong diagnostic and prognostic potential, even at preclinical stages. The convergence of multimodal biomarker panels with artificial intelligence-based analytics is poised to transform early diagnosis, patient stratification, and precision-based therapeutic development in dementia.