Objective: The aims of this study were (a) to determine the frequency of APOE genotypes in dementia, (b) to relate e4 allele frequency to clinical symptomatology of dementia and (c) to relate e4 and assess risk factors for different types of dementia.
Design: Prospective clinical study setting older patients with dementia known to a community-based old age psychiatry service.
Sample: 101 patients fulfilling ICD 10 criteria for dementia.
Results: Replication of previous findings of an association between APOE4 and Alzheimer's disease: younger age of onset of dementia; family history of dementia; persecutory ideation; and (retrospectively determined) rate of competent decline. No association was found between APOE4 and vascular dementia. The association between APOE4 and 'mixed dementia' was intermediate between that of pure Alzheimer's disease and pure vascular dementia.
Conclusion: The results confirm the relationship between clinical features of dementia and APOE4 status. It may be that APOE can be used as an adjunct to clinical diagnosis.