# Alzheimer’s disease

Source: https://onco.cc/diagnoses/alzheimers-disease/  
OnCo record `alzheimers-disease` (Diagnosis). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Alzheimer’s disease is a brain disease that commonly causes dementia. Early-stage anti-amyloid medicines exist for a carefully selected group, and several older medicines can support cognitive symptoms.

## Summary

Alzheimer’s disease is defined pathologically by amyloid plaques and tau tangles. Clinically it often begins with memory of recent events, then spreads to language, visuospatial skill, and independence. Biomarkers (amyloid PET, cerebrospinal fluid, and emerging blood tests) can support the biological diagnosis. Disease-modifying antibodies that lower amyloid are approved in some regions for early symptomatic disease after amyloid confirmation, with MRI monitoring for ARIA. Cholinesterase inhibitors and memantine remain symptom treatments. They do not change the underlying pathology. Treating the wrong subtype can add harm without benefit.

## Fields

- Kind: Diagnosis
- Last checked: 2026-09-21
- Tags: dementia-atlas
- Group: dementia
- Burden: Alzheimer’s disease is the dementia type this atlas covers in the most depth, including early-stage anti-amyloid medicines and several symptom treatments.
- Subtypes: Mild cognitive impairment due to Alzheimer’s disease; Mild dementia due to Alzheimer’s disease; Moderate to severe dementia of the Alzheimer’s type
- Biomarkers: Amyloid PET; CSF amyloid and tau; Plasma amyloid and p-tau research assays; ApoE ε4 (ARIA-risk discussion); MRI for ARIA monitoring

## Standard of care

- Assessment: Clinical diagnosis first. Confirm amyloid pathology before starting an anti-amyloid antibody. Discuss bleeding risk, MRI access, infusion logistics, and ApoE ε4. ([Amyloid PET](https://onco.cc/technologies/da-tech-amyloid-pet/), [CSF amyloid and tau](https://onco.cc/technologies/da-tech-csf-biomarkers/), [Lecanemab](https://onco.cc/drugs/da-lecanemab/), [Donanemab](https://onco.cc/drugs/da-donanemab/))
- Early symptomatic Alzheimer’s disease with confirmed amyloid: Where licensed and accessible, lecanemab or donanemab may be considered with MRI monitoring. These are not cures and do not restore lost function. ([Lecanemab](https://onco.cc/drugs/da-lecanemab/), [Donanemab](https://onco.cc/drugs/da-donanemab/), [CLARITY AD](https://onco.cc/trials/da-trial-clarity-ad/), [TRAILBLAZER-ALZ 2](https://onco.cc/trials/da-trial-trailblazer-alz2/))
- Cognitive symptoms across stages: Donepezil, rivastigmine, or galantamine, and memantine in moderate to severe disease, as individually indicated. These are symptom treatments. ([Donepezil](https://onco.cc/drugs/da-donepezil/), [Rivastigmine](https://onco.cc/drugs/da-rivastigmine/), [Galantamine](https://onco.cc/drugs/da-galantamine/), [Memantine](https://onco.cc/drugs/da-memantine/))
- Agitation associated with dementia due to Alzheimer’s disease: Look first for pain, delirium, environment, and unmet need. Brexpiprazole has a specific US indication after that assessment, not as a first or as-needed sedative. ([Brexpiprazole](https://onco.cc/drugs/da-brexpiprazole/))

## State of the art

- Two amyloid-lowering antibodies have traditional or full US approval for early symptomatic Alzheimer’s disease after amyloid confirmation.
- ARIA (imaging swelling or bleeding) is a boxed risk and needs a monitoring plan before the first infusion.
- Most people living with Alzheimer’s disease are not candidates for these antibodies because of stage, comorbidities, imaging, or access.

## Open problems

- Who benefits enough to justify ARIA risk, infusion burden, and cost remains an individual clinical judgement.
- People with mixed or atypical presentations are under-represented in antibody trials.
- There is still no approved disease-modifying treatment once dementia is moderate or severe.
- Blood tests may triage who needs PET or spinal fluid, but they are not a stand-alone diagnosis.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Alzheimer%27s_disease
- FDA: Leqembi traditional approval: https://www.fda.gov/news-events/press-announcements/fda-converts-novel-alzheimers-disease-treatment-traditional-approval
- FDA: Kisunla approval: https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-treatment-adults-alzheimers-disease
- NICE NG97: https://www.nice.org.uk/guidance/ng97

## Connected records

- diagnoses: [Dementia (umbrella)](https://onco.cc/diagnoses/dementia/), [Frontotemporal dementia](https://onco.cc/diagnoses/frontotemporal-dementia/), [Mild cognitive impairment](https://onco.cc/diagnoses/mild-cognitive-impairment/), [Mixed dementia](https://onco.cc/diagnoses/mixed-dementia/)
- roadmaps: [Anti-amyloid medicines](https://onco.cc/roadmaps/da-roadmap-anti-amyloid/)
- collections: [ClinicalTrials.gov](https://onco.cc/collections/da-collection-clinicaltrials/)
- ideas: [Antibody trials that enrol mixed and comorbid disease](https://onco.cc/ideas/da-idea-inclusive-anti-amyloid-trials/), [Blood test before PET or lumbar puncture](https://onco.cc/ideas/da-idea-blood-first-triage/), [Make carer outcomes a primary trial endpoint](https://onco.cc/ideas/da-idea-carer-outcome-primary/)
- fronts: [Anti-amyloid treatment](https://onco.cc/fronts/da-front-anti-amyloid/), [Anti-tau research](https://onco.cc/fronts/da-front-anti-tau/), [Fluid biomarkers](https://onco.cc/fronts/da-front-fluid-biomarkers/), [Imaging](https://onco.cc/fronts/da-front-imaging/)
- technologies: [Amyloid PET](https://onco.cc/technologies/da-tech-amyloid-pet/), [Anti-amyloid antibodies](https://onco.cc/technologies/da-tech-anti-amyloid-mab/), [ApoE testing](https://onco.cc/technologies/da-tech-apoe-testing/), [Blood Alzheimer biomarkers](https://onco.cc/technologies/da-tech-blood-biomarkers/), [Brain MRI](https://onco.cc/technologies/da-tech-mri/), [Cholinesterase inhibitors](https://onco.cc/technologies/da-tech-cholinesterase-inhibitors/), [CSF amyloid and tau](https://onco.cc/technologies/da-tech-csf-biomarkers/), [Tau-directed therapeutics](https://onco.cc/technologies/da-tech-tau-therapeutics/)
- targets: [Acetylcholinesterase](https://onco.cc/targets/da-target-ache/), [Amyloid-beta](https://onco.cc/targets/da-target-amyloid-beta/), [Tau](https://onco.cc/targets/da-target-tau/)
- drugs: [Aducanumab](https://onco.cc/drugs/da-aducanumab/), [Brexpiprazole](https://onco.cc/drugs/da-brexpiprazole/), [Donanemab](https://onco.cc/drugs/da-donanemab/), [Donepezil](https://onco.cc/drugs/da-donepezil/), [Galantamine](https://onco.cc/drugs/da-galantamine/), [Lecanemab](https://onco.cc/drugs/da-lecanemab/), [Memantine](https://onco.cc/drugs/da-memantine/), [Remternetug](https://onco.cc/drugs/da-remternetug/), [Rivastigmine](https://onco.cc/drugs/da-rivastigmine/)
- companies: [Biogen](https://onco.cc/companies/da-biogen/), [Eisai](https://onco.cc/companies/da-eisai/), [Eli Lilly](https://onco.cc/companies/da-lilly/)
- institutions: [National Institute on Aging](https://onco.cc/institutions/da-nia/), [UCL](https://onco.cc/institutions/da-ucl-dementia/)
- pathways: [Amyloid and tau cascade (simplified)](https://onco.cc/pathways/da-pathway-amyloid-tau/)
- terms: [Amyloid PET](https://onco.cc/terms/da-term-amyloid-pet/), [ARIA](https://onco.cc/terms/da-term-aria/)
- trials: [CLARITY AD](https://onco.cc/trials/da-trial-clarity-ad/), [ENGAGE](https://onco.cc/trials/da-trial-engage/), [EXPEDITION 3](https://onco.cc/trials/da-trial-expedition3/), [TRAILBLAZER-ALZ 2](https://onco.cc/trials/da-trial-trailblazer-alz2/)
- people: [Alois Alzheimer](https://onco.cc/people/alois-alzheimer/)
- bottlenecks: [Late and uneven diagnosis](https://onco.cc/bottlenecks/da-bn-late-diagnosis/), [Trial populations that skip mixed disease](https://onco.cc/bottlenecks/da-bn-trial-exclusion/), [Wrong-subtype treatment](https://onco.cc/bottlenecks/da-bn-subtype-misclassification/)
- pairings: [Lecanemab with MRI monitoring](https://onco.cc/pairings/da-pair-lecanemab-mri/)
- key papers: [Lecanemab in Early Alzheimer’s Disease (CLARITY AD)](https://onco.cc/key-papers/da-paper-clarity-ad/)

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JSON: https://onco.cc/api/v1/entities/alzheimers-disease.json