MEASUREMENT OF DEMENTIA IN INDIVIDUALS WITH MENTAL-RETARDATION - COMPARISON BASED ON PPVT AND DEMENTIA RATING-SCALE

The major purpose of this study was to examine the application of a dementia rating scale that is frequently used in the general population, with the mentally retarded population. The onset of age-related dementia was compared for individuals with and without Down Syndrome (DS) by ratings on this scale. The Dementia Rating Scale (DRS) was administered to 54 individuals with DS and 46 NonDS individuals with mental retardation between ages 20 and 65 years, along with the Peabody Picture Vocabulary, Matrix Analogies, and Draw-A-Person tests. Factor analysis yielded two meaningful factors. We demonstrated that the scale is appropriate for the mentally retarded samples and is a valid measure of dementia because a sudden decrement was detected by the scale among the DS sample at age 50 and above.