Of all the health issues that loom large with age, memory loss is among those that provoke the most worry. A big reason is the uncertainty: people often wonder if their occasional memory slips are just a normal part of growing old or a sign of impending Alzheimer’s disease, the most common form of dementia. A new study of older adults, published in today’s issue of the journal Neurology, sheds some light—and perhaps offers a bit of reassurance—about the connection between self-reported memory loss and a diagnosis of dementia. Over a 10-year period as 70-somethings turned into 80-somethings, about 1 in 6 developed dementia. About 80% had reported memory changes. But it took about nine years from the first self-report of a memory change to a diagnosis of mild cognitive impairment, an intermediate stage between normal memory loss and dementia. The transition to dementia usually took about 12 years.