Alzheimer movement re-examined 25 years later: Is it a "disease" or a senile condition in medical nature?

Dementia in the elderly used to be rare, but why has it become a major soci al threat today? There can be many potential answers, but an ultimate one i s clear: the longer life expectancy today. This knowledge indicates that "a dvanced aging" is a primary suspect in the origin of senile dementia. If so , then why can many elderly remain healthy at the same old age? We know, fo r example, that elderly people commonly have a certain degree of atheroscle rosis and osteoporosis, but only some of them develop severe clinical sympt oms at the same age. These different outcomes generally can be explained by "risk factors" in life (exercise, diet, individual background, etc). It th us appears to be a general pattern that advanced aging (after age 80) will set the stage for various senile disorders, but risk factors largely determ ine the onset age as well as individual specificity of their clinical manif estations. In this context, senile disorders including senile dementia woul d differ fundamentally from the pathogen-caused conventional diseases (AIDS , polio, cancer, Down's, etc.) by origin, incidence, and intervention strat egy. This view would call into question the current definition of senile de mentia as a conventional "disease" (Alzheimer's). The term "Alzheimer's dis ease" originally referred to "midlife" dementia, but it is defined today to be the same medical entity as senile dementia on the basis that they both display the same hallmarks and symptoms despite their onset age difference. Now, after in-depth scrutiny, we finally come to realize that they are not the same disease, but as different as heart failure at midlife versus the "same" failure at advanced age (i.e., a conventional disease versus a senil e condition). Thus, by eliminating the age difference, the new definition h as converted a senile condition into a conventional "disease", thereby chan ging the course of its scientific inquiry to miss the main targets. This ma y be why after extensive studies for 25 years, the origin of senile dementi a has remained an enigma.