Is functional decline necessary for a diagnosis of Alzheimer's disease?

Dement Geriatr Cogn Disord. 2007;24(5):375-9. doi: 10.1159/000109268. Epub 2007 Oct 3.


Background: The purpose of this study is to examine baseline differences and annualized cognitive and functional change scores in mild Alzheimer's disease (AD) patients with and without impaired activities of daily living (ADL).

Methods: We recruited 267 mild probable AD patients with at least 1 year of follow-up (NINCDS-ADRDA criteria, MMSE>or=20). Based on initial ADL scores, they were divided into 2 groups: unimpaired (n=40) and impaired (n=227). We compared the differences in annualized change scores on MMSE, Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog), ADL and Clinical Dementia Rating sum of box score (CDR-SB) for patients with and without functional impairment at baseline.

Results: The group with unimpaired ADL at baseline had a significantly shorter symptom duration (p=0.01) and better neuropsychological test scores at baseline (p<0.001) than those with impaired ADL. The annualized cognitive and functional change of each group from baseline to 1-year follow-up was not significantly different on the MMSE, ADAS-cog, CDR-SB, Physical Self-Maintenance Scale and Instrumental Activities of Daily Living. After 1 year, 56% of the initially unimpaired group and 6% of the initially impaired group reported no ADL impairment.

Conclusions: Our study suggests that functional decline should not be required for the diagnosis of mild AD.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activities of Daily Living*
  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / complications
  • Alzheimer Disease / diagnosis*
  • Alzheimer Disease / physiopathology
  • Analysis of Variance
  • Chi-Square Distribution
  • Cognition Disorders / complications*
  • Cognition Disorders / diagnosis
  • Cognition Disorders / physiopathology
  • Female
  • Humans
  • Male
  • Mental Status Schedule
  • Neuropsychological Tests
  • Severity of Illness Index