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J Neurol Neurosurg Psychiatry. Sep 2003; 74(9): 1206–1209.
PMCID: PMC1738690

The prevalence and causes of dementia in people under the age of 65 years


Objectives: To determine the prevalence of dementia in people under the age of 65 in a large catchment area, and use these figures to estimate the number of younger people affected by dementia in the UK.

Design: Epidemiological catchment area prevalence survey.

Setting: The London boroughs of Kensington and Chelsea, Westminster, and Hillingdon with a total population of 567 500 people.

Participants: All residents of the catchment area with dementia, where the illness began before the age of 65 years. Participants were notified to the study by medical and care professionals. The diagnosis and age of onset was established from all available health and social care records. In total, 227 people were identified, of whom 185 fulfilled the inclusion criteria of having a dementia which started before their 65th birthday.

Main outcome measures: Diagnosis of dementia and differential diagnosis of the cause of the dementia.

Results: The prevalence of dementia in those aged 30–64 was 54.0 per 100 000 (95% CI 45.1 to 64.1 per 100 000). For those aged 45–64 years, the prevalence was 98.1 per 100 000 (95% CI 81.1 to 118.0 per 100 000). From the age of 35 onwards, the prevalence of dementia approximately doubled with each 5 year increase in age. Extrapolating these figures nationally suggests that there are 18 319 (15 296–21 758) people with dementia under the age of 65 in the UK.

Conclusions: The study confirms previous "guestimates" of the number of younger people affected by dementia in UK. The prevalence figures generated are robust, and are supported by other smaller and targeted prevalence surveys. The prevalence figures provided by this study will allow health planners to accurately estimate need and plan services.

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Selected References

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  • McGonigal G, Thomas B, McQuade C, Starr JM, MacLennan WJ, Whalley LJ. Epidemiology of Alzheimer's presenile dementia in Scotland, 1974-88. BMJ. 1993 Mar 13;306(6879):680–683. [PMC free article] [PubMed]
  • Newens AJ, Forster DP, Kay DW, Kirkup W, Bates D, Edwardson J. Clinically diagnosed presenile dementia of the Alzheimer type in the Northern Health Region: ascertainment, prevalence, incidence and survival. Psychol Med. 1993 Aug;23(3):631–644. [PubMed]
  • Woodburn K, Johnstone E. Ascertainment of a population of people with early-onset dementia in Lothian, Scotland. Int J Geriatr Psychiatry. 1999 May;14(5):362–367. [PubMed]
  • Ratnavalli E, Brayne C, Dawson K, Hodges JR. The prevalence of frontotemporal dementia. Neurology. 2002 Jun 11;58(11):1615–1621. [PubMed]
  • Jarman B. Identification of underprivileged areas. Br Med J (Clin Res Ed) 1983 May 28;286(6379):1705–1709. [PMC free article] [PubMed]
  • McKhann G, Drachman D, Folstein M, Katzman R, Price D, Stadlan EM. Clinical diagnosis of Alzheimer's disease: report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer's Disease. Neurology. 1984 Jul;34(7):939–944. [PubMed]
  • Román GC, Tatemichi TK, Erkinjuntti T, Cummings JL, Masdeu JC, Garcia JH, Amaducci L, Orgogozo JM, Brun A, Hofman A, et al. Vascular dementia: diagnostic criteria for research studies. Report of the NINDS-AIREN International Workshop. Neurology. 1993 Feb;43(2):250–260. [PubMed]
  • McKeith IG, Galasko D, Kosaka K, Perry EK, Dickson DW, Hansen LA, Salmon DP, Lowe J, Mirra SS, Byrne EJ, et al. Consensus guidelines for the clinical and pathologic diagnosis of dementia with Lewy bodies (DLB): report of the consortium on DLB international workshop. Neurology. 1996 Nov;47(5):1113–1124. [PubMed]
  • Rosen WG, Terry RD, Fuld PA, Katzman R, Peck A. Pathological verification of ischemic score in differentiation of dementias. Ann Neurol. 1980 May;7(5):486–488. [PubMed]
  • Hughes CP, Berg L, Danziger WL, Coben LA, Martin RL. A new clinical scale for the staging of dementia. Br J Psychiatry. 1982 Jun;140:566–572. [PubMed]
  • Reisberg B, Borenstein J, Salob SP, Ferris SH, Franssen E, Georgotas A. Behavioral symptoms in Alzheimer's disease: phenomenology and treatment. J Clin Psychiatry. 1987 May;48 (Suppl):9–15. [PubMed]
  • Teunisse S, Derix MM, van Crevel H. Assessing the severity of dementia. Patient and caregiver. Arch Neurol. 1991 Mar;48(3):274–277. [PubMed]
  • Blessed G, Black SE, Butler T, Kay DW. The diagnosis of dementia in the elderly. A comparison of CAMCOG (the cognitive section of CAMDEX), the AGECAT program, DSM-III, the Mini-Mental State Examination and some short rating scales. Br J Psychiatry. 1991 Aug;159:193–198. [PubMed]
  • Sulkava R, Wikström J, Aromaa A, Raitasalo R, Lehtinen V, Lahtela K, Palo J. Prevalence of severe dementia in Finland. Neurology. 1985 Jul;35(7):1025–1029. [PubMed]
  • Kokmen E, Beard CM, Offord KP, Kurland LT. Prevalence of medically diagnosed dementia in a defined United States population: Rochester, Minnesota, January 1, 1975. Neurology. 1989 Jun;39(6):773–776. [PubMed]
  • Stevens Tim, Livingston Gill, Kitchen Ginnette, Manela Monica, Walker Zuzana, Katona Cornelius. Islington study of dementia subtypes in the community. Br J Psychiatry. 2002 Mar;180:270–276. [PubMed]

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