As a physician, I always told my older patients that a decline in memory as they aged had nothing to do with the risk for Alzheimer’s. I have repeated the same thing in this blog several times, for instance, here. Apparently, I’ve been wrong.
As the results of a number of research studies presented at the Alzheimer's Association International Conference (AAIC) in July 2013, get around, they will worry a lot of older people and bring them to their doctors for testing. According to the studies, people with subjective complaints of cognitive decline (for example, memory loss) but no objective findings (ie, their tests for impaired thinking are normal) are considerably more likely to progress to mild cognitive impairment (MCI) or dementia than people who have no such complaints. In plain English, if you think your memory is getting worse as you age, you have good reason to be concerned about Alzheimer’s or other dementia even if your doctor tells you you’re fine.
These findings are in complete contradiction to what most physicians believe, which is that memory complaints are a normal sign of aging and have nothing to do with the Alzheimer’s.
One of the doctors interviewed acknowledged that “you clearly don’t want to worry everybody who’s aging,” but, it seems to me, since so many people experience worsening memory as we age, these findings are going to worry almost everybody. I can just see the rush to doctors’ offices.
Each of these studies has a different design. Some look at people who have already come to their doctors with symptoms; others are more reliable studies of the unselected general population. Some include data about whether family or friends notice the symptoms; others don’t. At least one study includes autopsy results (the only way to definitively diagnose Alzheimer’s). One study includes progression to MCI as well as to dementia. Another includes MCI or dementia from any cause, not just Alzheimer’s. The advantage of these multiple designs is that the results are less likely to be due to some flaw in the design. The disadvantage is that none of the studies has been explicitly replicated, which is usually necessary to draw valid conclusions.
But all point in the same direction: if you think your memory is getting worse (or you’re having trouble with other kinds of thinking), you have a good chance of progressing toward something more serious. One study suggested that your chances are about two out of three.
As usual, these kinds of studies raise more questions than they answer.
- Is your risk increased (and by how much) if your PET scans (like mine) are normal?
- If the only problem you have is remembering names, how serious is that?
- If your only symptom is not being able to find the right word exactly when you need it, is the risk of progressing to MCI or dementia higher?
- Is the real problem only with Alzheimer’s or does it include other causes of cognitive impairment?
It will be interesting to see how these findings affect both patients who worry about their memory and doctors who care for them.