Mild cognitive impairment (MCI) is a stage which can sometimes - although not always - lead on to Alzheimer's disease. A study of 1,158 people by researchers at Rush University Medical Center in Chicago has found that people with MCI often go downhill quickly. The average age of the participants in the study was 79. 149 of them had Alzheimer's disease, 395 had MCI and 614 had no thinking or memory problems. The participants took regular tests of their memory and thinking skills. The thinking skills of people with MCI declined twice as fast, per year, as those who had no cognitive problems while the skills of those with Alzheimer's disease declined four times as fast.
You can find out more about this research at