In the New York Times on March 21st, Jane Gross observed that a new report from the Alzheimer’s Association shows a 10 percent increase in the number of people who are suffering from Alzheimer’s disease. She writes, “…the report includes the startling finding that 200,000 to 500,000 people younger than 65 have some form of dementia…”

I’m not clear why she finds this startling: As procedures for early assessment and general awareness of the symptoms of the disease increase, increasingly, middle-aged people will receive the diagnosis of Alzheimer’s. That sounds like a terrible thing, but in fact, it is simply the acceptance of a barely acknowledged truth: That Alzheimer’s is not exclusively a disease of old age. (For further information about the prevalence of dementia in midlife, look at the Alzheimer’s Association’s report, Early-Onset Dementia: A National Challenge, A Future Crisis. Current research suggests that the seeds of Alzheimer’s are sown in midlife. Most important: The best time to treat the disease (and probably the only time that treatment can be effective) is in a very early stage, before neurons are crippled and begin to die. For more information on this, you may want to read Chapters 17 and 18 of Carved in Sand. The ease and accuracy of early assessment will depend on the effectiveness of new biomarkers that are currently under study by the Alzheimer’s Disease Neuroimaging Initiative (ADNI) and other groups.