Incidence of dementia

The Alzheimer’s Society estimates that around 800,000 people in the UK have dementia. However, it is difficult to arrive at a precise figure because many cases - perhaps as many as 44% - are not diagnosed, and dementia is often not specified as a main or contributory cause of death.

The incidence of dementia is expected to rise rapidly - to 1,000,000 in 2021 and 1,700,000 in 2051.

The number of people with dementia in England is increasing and will reach 1 million by 2051

Chart Source: Knapp at al. (2007) Dementia UK: Report to the Alzheimer's Society. King's College London and London School of Economics and Political Science
  1. Prevalence rises rapidly from age 65, when it affects 1.3% of the population, more than doubling every 5 years up to 32.5% at age 95. Prevalence rates appear to vary little between countries, though they identify and diagnose dementia in different ways. Dementia can also affect people as young as 30. Factors including age, genetic background, medical history and lifestyle may determine onset. Dementia affects all socio-economic groups.
  2. The Dementia UK report used the Expert Delphi Consensus methodology to produce best estimates of prevalence of dementia for 2006-7 and onwards using currently available data.

What does it mean to have dementia? Note down the main signs and symptoms you associate with this disease.


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