Alzheimer's disease: from molecular pathways to therapies

Alzheimer disease (AD) is the most common neurodegenerative disorder and a leading cause of dementia worldwide. With accelerating population aging, its incidence continues to rise, imposing a substantial burden on public health systems and society. Despite extensive advances in research, currently available therapies remain largely symptomatic and have limited capacity to halt or reverse disease progression. Recent progress in understanding the molecular and cellular mechanisms underlying AD has driven the development of targeted therapeutic strategies, particularly immunotherapies directed against amyloid-β (Aβ) and tau pathology. However, the pathogenesis of AD is highly complex and multifactorial, underscoring the need for a more integrated understanding of the interactions among diverse pathological processes and the identification of additional therapeutic targets. Here, we provide a systematic synthesis of the core pathological mechanisms of AD and their interconnected molecular pathways, together with a comprehensive overview of current targeted therapeutic strategies. We highlight recent advances in Aβ- and tau-directed immunotherapies and further examine emerging interventions targeting neuroinflammation, metabolic dysregulation, the gut microbiota, lifestyle-related factors, and neurogenesis, evaluating their potential based on evidence from both clinical and preclinical studies. By integrating mechanistic insights with therapeutic developments, this review outlines key opportunities and challenges in the evolving landscape of AD treatment. These perspectives may inform the development of next-generation disease-modifying therapies and contribute to a more comprehensive framework for understanding the pathogenesis and treatment of AD.