=== Prævalens ===
AD's prævalens i befolkninger afhænger af forskellige faktorer, heriblandt incidens og overlevelse. Da AD's incidens stiger med alderen er det særligt vigtigt at inkludere den pågældende befolkningsgruppes gennemsnitsalder. [[WHO]] har skønnet at i 2005 led 0,379% af befolkningen på verdensplan af demens, og at prævalensen ville stige til 0,441% i 2015 og videre til 0,556% i 2030.<ref name="isbn9789241563369">{{cite book|last=World Health Organization|title=Neurological Disorders: Public Health Challenges|publisher=World Health Organization|year=2006|location=Switzerland|pages=204–207|url=http://www.who.int/mental_health/neurology/neurodiso/en/index.html|isbn=978-92-4-156336-9|access-date=12. december 2016|archive-date=10. februar 2010|archive-url=https://web.archive.org/web/20100210144936/http://www.who.int/mental_health/neurology/neurodiso/en/index.html|url-status=live}}</ref> Andre studier har nået til lignende konklusioner.<ref name="pmid16360788">{{vcite journal | vauthors = Ferri CP, Prince M, Brayne C, Brodaty H |display-authors=etal | title = Global Prevalence of Dementia: A Delphi Consensus Study | journal = Lancet | volume = 366 | issue = 9503 | pages = 2112–7 | year = 2005 | pmid = 16360788 | pmc = 2850264 | doi = 10.1016/S0140-6736(05)67889-0 | month = December }}</ref> Et andet studie skønnede at i 2006 ville 0,40% af verdens befolkning være ramt af AD, og at prævalensraten ville tredoble frem til 2050.<ref name="Brookmeyer2007">2006-prævalensestimat:
* {{vcite journal | vauthors = Brookmeyer R, Johnson E, Ziegler-Graham K, Arrighi HM | title = Forecasting the global burden of Alzheimer's disease | journal = Alzheimer's & Dementia | volume = 3 | issue = 3 | pages = 186–91 | year = 2007 | pmid = 19595937 | doi = 10.1016/j.jalz.2007.04.381 | url = http://works.bepress.com/cgi/viewcontent.cgi?article=1022&context=rbrookmeyer | month = July | access-date = 18. juni 2008 | archive-date = 7. december 2008 | accessdate = 12. december 2016 | archivedate =  7. december 2008 | archiveurl = https://web.archive.org/web/20081207025403/http://works.bepress.com/cgi/viewcontent.cgi?article=1022&context=rbrookmeyer }}
* {{vcite journal|url=http://un.org/esa/population/publications/wpp2006/WPP2006_Highlights_rev.pdf|format=PDF|access-date=27. august 2008|year=2007|title=World population prospects: the 2006 revision, highlights|publisher=Population Division, Department of Economic and Social Affairs, United Nations|version=Working Paper No. ESA/P/WP.202|author1=<!-- Please add first missing authors to populate metadata. -->|archive-date=19. august 2008|accessdate=12. december 2016|archivedate=19. august 2008|archiveurl=https://web.archive.org/web/20080819191533/http://www.un.org/esa/population/publications/wpp2006/WPP2006_Highlights_rev.pdf}}</ref>
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