One of the risk factors for developing Alzheimer's disease is a poor educational level. This has been shown in a number of epidemiological studies. But now a report from the Albert Einstein College of Medicine in New York has added a new twist. Their report, which is published in the journal Neurology, shows that the effect of having a higher education is biphasic. If one accepts that the patient moves through different stages, from impaired cognitive function to pre-dementia, and then an accelerated decline stage leading to the diagnosis of Alzheimer's. The theory of "cognitive reserve" implies that more education delays the acceleration phase of decline, due to this reserve of brain-power. However, after the stage of acceleration, the rate of decline picks up more in those with greater education, compared with the less-educated patients. In other words, the early signs of dementia may be masked in persons with higher educational achievement.

This is truly "good news, bad news". The chief investigator, Dr Charles Hall, summarizes the findings this way: "Higher levels of education delay the onset of dementia, but once it begins, the accelerated memory loss is more rapid in people with more education. . . . A person with 16 years of formal education would experience a rare of decline that is 50% faster than someone with just 4 years of education."

You can read more about the stages of the disease at the Alzheimer's Association website.