1. Introduction 2. Alzheimer's neuropathology in Down syndrome: From gestation to old age 3. The contribution of inflammation to Alzheimer's disease in Down syndrome 4. The role of cerebrovascular disease in aging and Alzheimer's disease among people with Down syndrome 5. Oxidative stress and mTOR in Down syndrome brain: Link to Alzheimer's dysmetabolism, neuropathology, and possible therapies 6. Fluid biomarkers for Alzheimer's disease in Down syndrome: Current status and novel trends 7. Proteomic and metabolomic biomarkers of Alzheimer's disease: Opportunities to advance precision medicine and clinical trials 8. Magnetic resonance imaging biomarkers for cognitive decline in Down syndrome 9. PET imaging in Down syndrome and Alzheimer's disease 10. Genetics of Alzheimer's disease in adults with Down syndrome 11. Co-occurring medical conditions in aging adults with Down syndrome 12. Sleep in aging adults with Down syndrome and its association with Alzheimer's disease 13. Contributions of the neurological examination to the diagnosis of dementia in Down syndrome 14. Psychiatric issues in aging and dementia 15. Cognitive profile of aging and dementia 16. Clinical trials for Alzheimer's disease in Down syndrome 17. Future directions