[Dementias: current situation and future perspectives].

In this paper, the first one in a series of three complementary papers on dementias, we introduce the concept and evaluate the methods for diagnostic and the data provided by modern epidemiology. The current clinic criteria for the diagnosis of dementias are based on international instructions such as those included in the DSM-III-R (1987), and the ICD-10 (1992), and the criteria developed by the NINCDS-ADRDA or the CERAD. Such a disparity makes even more difficult the transcultural reliability of epidemiological information. The differentiation with pseudodementias, being the depressive one the most frequent of them (75%), the inclusion of the denominated dementia-AIDS complex, or those dementias related with the alcoholic illness have special relevance. In Europe the more solid studies proceed from the EURODEM group, and their results are consistent with the North American and Asiatic ones, pointing all of them out an exponential growing of dementia with age, which is very similar in the different continents. The risk factors for the Alzheimer's disease and other dementias are discussed and contrasted with the contributions of the different reliable documental sources existing.