A LONGITUDINAL COMPARISON OF COGNITIVE AND ADAPTIVE-CHANGES IN SUBJECTS WITH DOWNS-SYNDROME AND AN INTELLECTUALLY DISABLED CONTROL-GROUP

Sixty-seven subjects with karyotypically verified Down's syndrome (DS) and 48 matched controls without DS (DS-) were examined on adaptive, intellectual, memory, orientation and motor functions during a period of 41/2 years. The primary analysis compared changes in cognitive and adaptive functions in the two groups. Analysis of variance revealed th at in adults with DS, over the age of 50 years, functional loss was st atistically significant. Intelligence, memory and orientation function s deteriorated statistically significantly in 21/2 years. The decrease in adaptive and motor functions took 41/2 years to become statistical ly significant. No ageing effects were found in control subjects. Furt her investigation focused on the DSC population over 50 years old (n = 28). The effects of dementia and sensory deficits on adaptive and cog nitive decline were examined. Dementia was found to have a significant deteriorating influence on the majority of the adaptive and cognitive functions under study. Compared to the deteriorating influence of dem entia, the impact of hearing and visual deficiencies on functional los s was limited. Only visual impairment was related to a lesser performa nce of personal daily living skills. Hearing handicaps were not signif icantly related to functional decline.