Objective: The aim of the study was to determine which cognitive functions first deteriorate in Alzheimer's disease (AD) and to identify persons who would become demented 2 years following an initial examination.
Participants: A total of 2452 initially non-demented persons, aged 65-84 years and randomly drawn from the population, who were examined 2 years apart.
Measures: CAMCOG, the cognitive section of CAMDEX (The Cambridge Mental Disorders of the Elderly Examination). Fourteen composite measures were constructed of the 60 CAMCOG items.
Results: During the 2-year period, 102 developed AD; this group had significantly lower scores on all of the 14 composite measures at baseline examination than the subjects who remained non-demented. The incident demented were significantly older than the non-demented, had less formal schooling, were more often unskilled and had lower verbal intellectual level. Logistic regression analyses showed that especially higher age, together with reduced recent and remote memory, low category verbal fluency and attentional deficiency, characterized incident demented 2 years before the diagnosis was made.
Conclusions: Cognitive changes, which develop years before the AD diagnosis, can be identified by means of CAMCOG, but this instrument does not allow identification of persons who later develop AD with sufficient precision.
Copyright 1999 John Wiley & Sons, Ltd.