Performance of Greek demented and nondemented subjects on the Greek version of the Mattis Dementia Rating Scale. A validation study.

A translated version of the Mattis Dementia Rating Scale (DRS) into Greek ((DRS-GR) was applied to a sample of Greek population (N = 356) comprising normal middle-aged and elderly subjects (controls), as well as patients suffering from Parkinson's (PD) and Alzheimer's disease (AD) to test its reliability and validity. A well-known dementia screening instrument, the Mini Mental State Examination test (MMSE), and a nonverbal measure of abstract reasoning, the Raven Coloured Progressive Matrices, were employed as measures of DRS-GR concurrent validity. Reliability analysis was satisfactory with Cronbach's alpha reaching 0.