Progression of mild cognitive impairment to dementia

a challenge to current thinking

BUSSE, ANJA DPsych
ANGERMEYER, MATTHIAS C. MD
RIEDEL-HELLER, STEFFI G. MD, MPH

ANJA BUSSE, DP DPsych sych, MATTHIAS C. ANGERMEYER, ANGERMEYER, MD, STEFFI G. RIEDEL-HELLER, MD, MPH, Leipzig Longitudinal Study of the Aged LEILA75+, Department of Psychiatry, University of Leipzig, Germany

Correspondence: Professor Steffi G. Riedel-Heller, MPH, Department of Psychiatry, University of Leipzig, Johannisallee 20, 04317 Leipzig, Germany. Tel.: +49 341 97 24 530; fax: +49 341 97 24 539. Email: [email protected]

Declaration of interest None. Funding detailed in Acknowledgements.

(First received 29 June 2005, final revision 20 March 2006, accepted 2 June 2006)

British Journal of Psychiatry 189(5):p 399-404, November 2006.

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%.

Aims

This study examines the time-dependent evolution from mild cognitive impairment to dementia. Current assumptions regarding yearly and lifetime conversion rates are challenged.

Method

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.