EPIDEMIOLOGY OF DEMENTIA AND ALZHEIMERS-DISEASE

The prevalence of dementia in subjects 65 years and older in North Ame rica is approximately 6%-10%, with Alzheimer's disease (AD) accounting for two-thirds of these cases. If milder cases are included the preva lence rates double. Both causative and associative genes for AD have n ow been identified. The search for nongenetic risk factors has been le ss conclusive. Only age and family history of dementia are consistentl y associated with AD in all studies, but putative, protective agents s uch as estrogen, non-steroidal anti-inflammatory agents (NSAIDs), and vitamin E are now undergoing clinical trials.