Prevalence of Alzheimer's disease and other dementing disorders in Pamplona, Spain.

We investigated the prevalence of dementing disorders in the city of Pamplona, Spain, using a door-to-door two-phase approach. We first administered the Cambridge Examination of Mental Disorders of the Elderly (CAMDEX) to all survivors, as of March 1, 1991, of a probability sample of the total population identified in 1989 (n = 1,127). Using specified diagnostic criteria, the study neurologists extensively investigated those subjects who screened positive on CAMDEX. We found 194 subjects affected by dementia, 119 had Alzheimer's disease; 51 vascular or mixed dementia, and 16 secondary dementia. The prevalence of both dementia and Alzheimer's disease increased steeply with advancing age and was consistently higher in women. The prevalence of combined vascular and mixed dementia increased less rapidly with age, and was generally higher in men. Alzheimer's disease was the most common type of dementia. Our prevalence figures for dementia and Alzheimer's disease are similar to those previously reported in Europe.