title: An Age Old Problem? Estimating the Impact of Dementia on Past Human Populations.
abstract: OBJECTIVE
  To model the impact of dementia on past societies.
  
  
  METHODS
  We consider multiple lines of evidence indicating elderly individuals to have been more common throughout the past than is frequently accepted. We then apply known dementia incidence/prevalence rates to plausible assumptions of past population structures to suggest prevalence in the past.
  
  
  RESULTS
  Dementia prevalence in premodern societies is likely to have been around 5% of the rate seen in modern, developed countries but with a total past incidence running into billions.
  
  
  CONCLUSIONS
  Dementia is often seen as a "modern" challenge that humans have not had to contend with before. We argue that this condition has had considerably greater effects than previously envisaged and is a challenge that humans have already withstood successfully, on one hand at a lower incidence but on the other without the considerable clinical, technological, and social advances that have been made in recent times.
authors.affiliation: 1 Bournemouth University, Poole, Dorset, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Smith
authors.affiliation: 2 University of Sheffield, UK.
authors.forename: Alison
authors.initials: A
authors.lastname: Atkin
authors.affiliation: 1 Bournemouth University, Poole, Dorset, UK.
authors.forename: Clare
authors.initials: C
authors.lastname: Cutler
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003704:Dementia / Q000453:epidemiology* / Q000266:history*; D005260:Female; D049668:History, 15th Century; D049669:History, 16th Century; D049670:History, 17th Century; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D049674:History, 21st Century; D049690:History, Ancient; D049691:History, Medieval; D006801:Humans; D008136:Longevity; D008297:Male; D008875:Middle Aged; D015995:Prevalence
keywords: active life expectancy; dementia; demography; epidemiology; history