[Nosologic framework of mental deterioration in aged subjects. From clinical practice to epidemiology]

The difficulty of defining a precise nosologic framework for mental decline is linked, on the one hand, to the contradictions surrounding the term normalcy as age increases, and, on the other, to the fact that mental decline has been mired for years under a term that must be definitively proscribed: "psycho-compartmental disorders of senescence". In this catch-all++ proscribed: "psycho-compartmental disorders of senescence". In this catch++-all it is, in fact, essential to identify diseases whose nature, prognosis and, above all, therapeutic approaches differ fundamentally one from the other; to confuse them is to risk dramatic consequences. Standardization of diagnostic criteria through the combined use of clinical data, the DSM III classification, scored tests (MMS, Hachinsky, etc.), as well as scannography, presently makes it possible to arrive at the diagnosis of dementia with reasonable accuracy. This standardization++ has its limits and is not necessarily useful in atypical cases. It is nevertheless an indispensable tool for epidemiological studies and therapeutic trials.