What causes Alzheimer's disease?

Alzheimer's is associated with amyloid plaques and tau tangles in the brain, but the causal chain is unsettled. Decades of amyloid-targeting drugs have produced at best modest clinical benefit. Other proposed contributors include neuroinflammation, vascular changes, mitochondrial dysfunction and infection.

Identifying the primary driver — and finding therapies that meaningfully alter disease course — remain the central open questions in dementia research.