Alzheimer's disease (AD) is the most common form of dementia.
The number of people living with dementia worldwide more than doubled from 20.2 million in 1990 to 43.8 million in 2016, with a further increase to an estimated 57.4 million in 2019.[6]GBD 2016 Dementia Collaborators. Global, regional, and national burden of Alzheimer's disease and other dementias, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurol. 2019 Jan;18(1):88-106.
https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(18)30403-4/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/30497964?tool=bestpractice.com
[7]GBD 2019 Dementia Forecasting Collaborators. Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: an analysis for the Global Burden of Disease Study 2019. Lancet Public Health. 2022 Feb;7(2):e105-25.
https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(21)00249-8/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/34998485?tool=bestpractice.com
The total number of people living with dementia is predicted to reach 83 million by 2030 and 153 million by 2050. Increases are caused mainly by increases in population ageing and growth; age-standardised both-sex prevalence is predicted to remain stable between 2019 and 2050.[7]GBD 2019 Dementia Forecasting Collaborators. Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: an analysis for the Global Burden of Disease Study 2019. Lancet Public Health. 2022 Feb;7(2):e105-25.
https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(21)00249-8/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/34998485?tool=bestpractice.com
Projected increases in case numbers show geographical variation, with smallest percentage changes in high-income Asia Pacific and western Europe, and largest changes in North Africa, the Middle East, and eastern sub-Saharan Africa.[7]GBD 2019 Dementia Forecasting Collaborators. Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: an analysis for the Global Burden of Disease Study 2019. Lancet Public Health. 2022 Feb;7(2):e105-25.
https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(21)00249-8/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/34998485?tool=bestpractice.com
In the US, 4% of the population has a diagnosis of dementia; AD accounts for approximately 60% to 70% of dementia cases.[8]Kramarow EA. Diagnosed dementia in adults age 65 and older:United States, 2022. Natl Health Stat Report. 2024 Jun;(203):1-9.
https://www.cdc.gov/nchs//data/nhsr/nhsr203.pdf
http://www.ncbi.nlm.nih.gov/pubmed/38912900?tool=bestpractice.com
In 2023, there were estimated 6.7 million people in the US living with AD, and this is projected to increase to an estimated 13.8 million by 2060.[9]Alzheimer's Association. 2023 Alzheimer's disease facts and figures. Alzheimers Dement. 2023 Apr;19(4):1598-695.
http://www.ncbi.nlm.nih.gov/pubmed/36918389?tool=bestpractice.com
The prevalence of AD in Europe has been estimated to be around 5% to 7%, with a reported incidence of 11.08 per 1000 person-years (95% CI 10.30 to 11.89); both increase with age.[10]Niu H, Álvarez-Álvarez I, Guillén-Grima F, et al. Prevalence and incidence of Alzheimer's disease in Europe: a meta-analysis. Neurologia. 2017 Oct;32(8):523-32.
http://www.elsevier.es/en-revista-neurologia-english-edition--495-articulo-prevalence-incidence-alzheimer39s-disease-in-S2173580817301232
http://www.ncbi.nlm.nih.gov/pubmed/27130306?tool=bestpractice.com
[11]Bacigalupo I, Mayer F, Lacorte E, et al. A systematic review and meta-analysis on the prevalence of dementia in Europe: estimates from the highest-quality studies adopting the DSM IV diagnostic criteria. J Alzheimers Dis. 2018;66(4):1471-81.
https://pmc.ncbi.nlm.nih.gov/articles/PMC6294583
http://www.ncbi.nlm.nih.gov/pubmed/30412486?tool=bestpractice.com
AD occurs more commonly in women than in men.[7]GBD 2019 Dementia Forecasting Collaborators. Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: an analysis for the Global Burden of Disease Study 2019. Lancet Public Health. 2022 Feb;7(2):e105-25.
https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(21)00249-8/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/34998485?tool=bestpractice.com
[10]Niu H, Álvarez-Álvarez I, Guillén-Grima F, et al. Prevalence and incidence of Alzheimer's disease in Europe: a meta-analysis. Neurologia. 2017 Oct;32(8):523-32.
http://www.elsevier.es/en-revista-neurologia-english-edition--495-articulo-prevalence-incidence-alzheimer39s-disease-in-S2173580817301232
http://www.ncbi.nlm.nih.gov/pubmed/27130306?tool=bestpractice.com
Prevalence of dementia is higher in black and Hispanic people than in white people.[12]Matthews KA, Xu W, Gaglioti AH, et al. Racial and ethnic estimates of Alzheimer's disease and related dementias in the United States (2015-2060) in adults aged ≥65 years. Alzheimers Dement. 2019 Jan;15(1):17-24.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6333531
http://www.ncbi.nlm.nih.gov/pubmed/30243772?tool=bestpractice.com
[13]Manly JJ, Jones RN, Langa KM, et al. Estimating the prevalence of dementia and mild cognitive impairment in the US: the 2016 health and retirement study harmonized cognitive assessment protocol project. JAMA Neurol. 2022 Dec 1;79(12):1242-9.
https://pmc.ncbi.nlm.nih.gov/articles/PMC9593315
http://www.ncbi.nlm.nih.gov/pubmed/36279130?tool=bestpractice.com
Early onset AD (age <60 years) is often inherited in an autosomal dominant pattern and accounts for <1% of cases.