Dementia and ethnicity.

Ethnic differences in rates of dementia nationally, within multiethnic communities, and internationally have important repercussions. The question "Do ethnic differences exist in rates of dementia?" is a crucial one that has implications for service delivery and also offers opportunities for future research on possible etiological factors. Epidemiological surveys suggest that ethnic and geographical differences do occur in rates of dementia, but cross-cultural surveys are fraught with problems. The need for further methodologically sound, cross-cultural comparative studies is paramount to confirm or disclaim the ethnic differences observed to date.