THE PSYCHOGERIATRIC ASSESSMENT SCALES - A MULTIDIMENSIONAL ALTERNATIVE TO CATEGORICAL DIAGNOSES OF DEMENTIA AND DEPRESSION IN THE ELDERLY

The Psychogeriatric Assessment Scales (PAS) provide an assessment of t he clinical changes seen in dementia and depression. Principal compone nts analysis and latent trait analysis were used to develop a set of s cales to summarize these clinical changes. There are three scales deri ved from an interview with the subject (Cognitive Impairment, Depressi on, Stroke) and three from an interview with an informant (Cognitive D ecline, Behaviour Change, Stroke). Results are reported on the reliabi lity and validity of these scales using data from clinical samples in Sydney and Geneva and a population sample from Canberra. The scales we re found to have excellent validity when judged against clinical diagn oses of dementia and depression and could distinguish Alzheimer's from vascular dementia. Cut-off points were developed to indicate correspo ndence between scale scores and clinical diagnoses. Percentile rank no rms were developed from the Canberra population sample. The PAS is eas y to administer and score and can be used by lay interviewers after tr aining. It is intended for application both in research and in service s for the elderly.