The past, present and future of Alzheimer's disease - part 1: the past

Background Alzheimer's disease (AD) was described in 1907, and since then it changed from a relatively rare condition to one of the most prevalent diseases.Objective To describe the evolution of the notions of dementias and AD, and to investigate the reasons for the increase in scientific interest in AD.Methods A historical analysis was carried out on knowledge about dementia, the site of mental activity, the relationships between brain diseases and mental activity, and on the advances in research about AD, since its discovery until the publication of the amyloid cascade hypothesis in 1992. A search was carried out in the National Library of Medicine (PubMed) for scientific articles that included the terms dementia or AD over 50 years, from 1972 to 2021.Results The scientific research on AD increased from 615 papers with the term AD in the first decade (1972-1981), to 100,028 papers in the last decade (2012-2021): an increase of 162.6 times whereas publications with the term dementia increased 28.6 times in the same period. In the 1960s and 1970s, a consensus was reached that AD is responsible for the majority of cases of dementia previously known as senile dementia. In the 1980s, beta-amyloid peptide was identified in the core of the senile plaque, hyperphosphorylated tau protein was found in neurofibrillary tangles, and a mutation was discovered in a hereditary form of AD.Conclusion The expansion of the concept of AD to include senile dementia, and the discoveries that occurred in the 1980s greatly expanded research in AD.