The Alzheimer's disease assessment scale (ADAS): An instrument for early diagnosis of dementia?

Abstract

AbstractWith the aim of detecting mild dementias, 94 elderly subjects who had been participating in a long‐term study since 1976 were studied by means of a new diagnostic instrument, the Alzheimer's Disease Assessment Scale (ADAS) (Rosen et al., 1984). Data available from intelligence tests performed during the course of the long‐term study were also analysed.On the basis of an independent clinical assessment, four subjects were rated as clearly demented, seven as possibly demented, and 83 as normal. A comparison of these three groups showed that the subjects classified as demented obtained significantly poorer scores on the ADAS than did the group of normal subjects. The cognitive section of the ADAS distinguished even better between the normal and the clearly demented subjects. On the other hand, there was no indication that the ADAS was specifically sensitive to degenerative types of dementia since the subject with the highest ADAS score was suffering from vascular dementia. There were significant correlations between the score on the ADAS and the subjects' previous or current intelligence level as assessed by means of two standard intelligence tests. However, no correlation was found between any deterioration in intelligence over time (8–10 years) and the ADAS score. The three groups did not differ significantly in intelligence quotient either at the beginning of the study (1976/78) or at its end in 1986; however, there were trends in this direction.