Objective: The aims were to (i) report the outcome of mild cognitive disorder (MCD) 3.6 years after initial interview and diagnosis; (ii) identify predictors of new cases of MCD. The hypotheses were that (i) persons with MCD are more likely to develop dementia than those without MCD; (ii) symptoms of anxiety or depression predict MCD caseness at follow-up.
Design: Longitudinal cohort study.
Setting: Community of elderly people (age 70-97 years).
Participants: 612 of 897 elderly subjects (mean 76 years) were reinterviewed. Of the 36 MCD cases originally identified, 25 were available at follow-up. 24 incident cases of MCD were identified.
Main outcome measures: ICD-10 dementia, DSM-III-R dementia, ICD-10 mild cognitive disorder diagnoses made by the Canberra Interview for the Elderly, tests of anxiety, depression, neuroticism and cognitive performance.
Main results: Of the original 25 MCD cases available at follow-up, two had a diagnosis of MCD, and three had a diagnosis of both ICD-10 and DSM-III-R dementia. The prevalence of MCD and DSM-III-R dementia at follow-up was no greater for MCD cases diagnosed at initial interview than in normal subjects at initial interview. There was, however, an increased prevalence of ICD-10 dementia among original MCD cases. At initial interview and at follow-up MCD cases were more anxious and depressed but had similar cognitive performance to normals. For incident cases of MCD the only significant predictor was age.
Conclusions: MCD cannot be seen to be a specific forerunner of dementia. Those with a diagnosis of MCD are distinguished more by their anxiety, depression and neuroticism than by their cognitive deficits.