INCIDENCE OF DEMENTIA AND COGNITIVE DECLINE IN OVER-75S IN CAMBRIDGE - OVERVIEW OF COHORT STUDY

This paper summarises the methods and some of the findings of a large cohort study of dementia and cognitive decline in subjects aged over 7 5 years in Cambridge, particularly regarding the incidence wave. From a sample of 1968 subjects previously studied in a prevalence study in 1985-1987, survivors were restudied at 2.4 years, in a two-stage desig n employing the Mini, Mental State Examination (MMSE) and the Cambridg e Examination for Mental Disorders of the Elderly (CAMDEX). High incid ence rates of dementia were found, which rose steeply with age, partic ularly for Alzheimer's disease. New minimal dementia and milder cognit ive impairment were also common. Cognitive de dine on the MMSE showed a near normal, non-bimodal distribution. The sample has since been res tudied at intervals for a total of up to 9 years to document longitudi nal cognitive change. Brains have been obtained for post mortem neurop athological and molecular biological study, particularly of the early sequential changes associated with cognitive decline and dementia.