I’ve come across an online “in advance of publication” report that would be funny if it were not so grim.

Let’s say you’re not as young as you once were . . . and your mind starts to slip. You have problems with various cognitive capacities — word finding, calculation, and the like. Are you suffering early Alzheimer’s Disease? You visit your doctor and he or she reassures you. There’s no dementia. But then, that news isn’t all good.

As part of a longer term study, a research team led by Valgeir Thorvaldsson at Göteborg University in Sweden followed 228 individuals without dementia from age 70 until the subjects died. In the final fifteen years of life, these normal men and women suffered substantial cognitive decline. The falloff began with changes in perception, 15 years out, and moved on to spatial ability, about 8 years before death, and then, at 6 to 7 years, problems in verbal performance. The researchers speculated that the relatively sharp increases in impairment might be related to cardiovascular problems.

So: You’re not demented, you’re in what is called "terminal decline."

Normal aging is not so benign as we had been led to believe. Or rather, as neurology progresses, the nature of the normal will change. Doctors will begin attending to the conditions that cause a drop-off in mental functioning and predict worse to come.