Alzheimer's disease, depression and normal ageing: Merit of simple psychomotor and visuospatial tasks

Introduction. A brief psychometric test battery was used to differentiate A lzheimer's disease (AD) patients from patients with depression and healthy age-matched control subjects. The purpose was to investigate the discrimina tive value of simple psychomotor and visuospatial tasks that were implement ed in a computer-assisted test battery. Methods. Manumotoric coordination, discrimination reaction time and perform ance on a visuospatial pattern-matching task were assessed. Subjects were 3 0 patients with the diagnosis of probable AD (mild to moderate), 22 patient s with a major depression and 15 healthy normal control subjects. Results. Discrimination reaction time separated the three groups most disti nctly, but general level of cognitive functioning was a significantly confo unding variable. There were no differences between the AD and the depressed patients when the MMSE was used as a covariate. Substantial deficiencies i n manumotoric coordination were found in both demented and depressed patien ts. The visual pattern-matching task yielded longer reaction times in both patient groups than in the control group. Conclusion. Translated into neuropsychological terms, these data suggest de ficiencies in basic central operations, a slowing of central information pr ocessing and attentional deficits in AD and depressed patients. Psychomotor tasks were able to distinguish effectively healthy elderly persons from AD and depressed patients. This test battery, however, appears to be limited in differentiating AD from depression. Copyright (C) 2000 John Wiley & Sons , Ltd.