title: Progression of mild cognitive impairment to dementia: a challenge to current thinking.
abstract: BACKGROUND
  Studies of conversion from mild cognitive impairment to dementia suggest a linear progression over time. Conversion rates during lifetime may extend to 80-90%.
  
  
  OBJECTIVE
  This study examines the time-dependent evolution from mild cognitive impairment to dementia. Current assumptions regarding yearly and lifetime conversion rates are challenged.
  
  
  METHODS
  A community sample of 1045 dementia-free individuals aged 75 years and over was examined by neuropsychological testing based on 6 years of observation.
  
  
  RESULTS
  Approximately 60-65% of people with mild cognitive impairment develop clinical dementia during their life. Progression from mild cognitive impairment to dementia appears to be time dependent, occurring primarily within the initial 18 months.
  
  
  CONCLUSIONS
  Further long-term studies are needed to examine the time-dependent evolution from mild cognitive impairment to dementia and to establish age-specific conversion rates during lifetime.
authors.affiliation: Department of Psychiatry, University of Leipzig, Johannisallee 20, 04317 Leipzig, Germany. ries@medizin.uni-leipzig.de
authors.forename: Anja
authors.initials: A
authors.lastname: Busse
authors.forename: Matthias C
authors.initials: MC
authors.lastname: Angermeyer
authors.forename: Steffi G
authors.initials: SG
authors.lastname: Riedel-Heller
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000523:psychology*; D003704:Dementia / Q000209:etiology*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011379:Prognosis