Ageing in higher functioning adults with Down's syndrome: an interim report in a longitudinal study.

Mildly and moderately mentally retarded adults, who live in the community, were examined for global changes in mental status and specific changes in auditory and visual memory over a period of 3-5 years. Twenty-eight subjects with Down's syndrome (DS) between the ages of 27 and 55 years were compared to 18 subjects without DS who were of similar IQ and age. The evaluation of mental status consisted of testing orientation of person, place and time, object naming, visuomotor coordination, and concentration. Auditory memory was tested with an adapted version of the Buschke Memory test. Visual memory testing consisted of matching shapes which were presented simultaneously and after delays of 0, 5 and 10s on a computer-controlled screen. No changes were found in test scores between an initial testing and follow-up testing up to 5 years later, indicating that ageing processes were not having a major impact in the cognitive functioning of these subjects. Furthermore, there was no indication of any generalized decline in performance suggestive of early symptoms of dementia among the older subjects with DS.