COGNITIVE CHANGES IN VERY OLD PERSONS WITH DEMENTIA - THE INFLUENCE OF DEMOGRAPHIC, PSYCHOMETRIC, AND BIOLOGICAL VARIABLES

Longitudinal changes in global cognitive functioning, indexed by the M ini-Mental State Examination (MMSE), in subjects with dementia (Alzhei mer's disease and vascular dementia) were examined. The roles of sever al demographic, psychometric, and biological indices in predicting cog nitive deterioration were also examined. The sample consisted of 36 ve ry old (M age at entry = 83.0 years, range = 75-95) adults with dement ia from a community-based study. Subjects were tested on two occasions separated by approximately 2.5 years. Results indicated significant l ongitudinal decline in MMSE scores over the retest interval; the avera ge decline was estimated as 2.43 (SD = 1.81) points per year. Several factors were associated with cognitive deterioration. Higher initial M MSE scores were associated with greater deterioration, whereas superio r forward digit span and Block Design at entry were associated with at tenuated decline, once differences in baseline severity were accounted for. By contrast, a variety of other putatively important variables e xhibited no relationship to decline, including age, gender, education, onset age, dementia type, backward digit span, as well as a number of biological parameters (e.g., vitamin B-12, folic acid). The results s uggest that although the magnitude of cognitive deterioration in demen tia is highly variable, several indicators may be useful predictors of future changes in cognitive functioning.