Education and the risk of Alzheimer's disease: Findings from the study of dementia in Swedish twins

The association between dementia and education was studied in 143 twin pair s discordant for dementia, using a matched-pair design, and in 221 dementia cases and 442 unrelated controls from the same twin registry, using a case -control design. Low education was defined as 6 years or less of schooling. Case-control analyses with prevalent cases showed low education to be a ri sk for Alzheimer's disease but not dementia in general. Low education did n ot significantly predict incident cases. In the matched-pairs analysis, whi ch controls for genetic and other familial influences, differences in educa tion between demented twins and twin partners were not statistically signif icant. However, for Alzheimer's disease, odds ratios resulting from matched pairs and case-control analyses were similar. Twins' comparative reports a bout intellectual involvement earlier in their lives suggest a long-standin g difference on this dimension, with less involvement by the twin who becam e demented.