Here is an important paper that will likely cause a lot of interest and debate. The work published in The New England Journal of Medicine (NEJM) describes the Framington Heart Study, participants of which have been under surveillance for dementia since 1975. This is an extensive analysis of 5205 persons 60 years of age or older. The main conclusion here is that the incidence of dementia has declined over the course of three decades in high-income countries. In the interest of full disclosure, I am not saying that I have read the manuscript carefully. The description of methodology in a typical NEJM paper is above me. However, the conclusions are exhilarating because recent projections have suggested that there would be a significant burden of dementia over the next four decades owing to longer life span and associated higher number of older persons at risk. The actual decrease reported by Sephardi and co-workers (up to 44% per epoch of the surveillance period) is quite interesting. The understanding of the underlying phenomena is clearly incomplete and delineation of possible causes is needed in order to accelerate the beneficial trend. These kinds of findings go against expectations and show that we really do not have a clue when it comes to cataclysmic predictions. At the dawn of the 20^th century people thought that horse manure would be the biggest environmental threat. And then cars came around… Incidentally, NEJM has the highest impact factor – higher than Science or Nature – which is kind of remarkable because this is, in fact, a rather specialized medical journal.

http://www.nejm.org/doi/full/10.1056/NEJMoa1504327