Benefits of early diagnosis of Alzheimer’s

I’m sometimes asked about the need for early and accurate diagnosis of Alzheimer’s. After all, there is no cure—what are we going to do about it? Yet the Alzheimer’s Association has also emphasized the need to accurately recognize Alzheimer’s as soon as possible. Why?

Here are a few benefits of early diagnosis:

• Excluding more treatable causes. Some estimate that only about 65% or so of dementia is Alzheimer’s, and some causes can be stopped or reversed. It is better to do this early in the disease course.
• Planning for the future. Things usually go better if there is a plan that can be followed.
• Guiding decisions on medications—some medications make cognition worse in Alzheimer’s disease. Recognizing Alzheimer’s will reduce the chance that these medications are taken.
• Possible benefits of early treatment. Alzheimer’s therapies now slow symptoms somewhat, but don’t stop or reverse the disease. Wouldn’t you rather preserve function when thinking and memory is relatively good, as opposed to when it’s worse? Medications like aducanumab may only be effective in these early stages.
• Participation in research. Many clinical trials only accept people at early disease stages, when the medication under investigation is most likely to work.
• Finally, while some people prefer not to know, many people get a sense of clarity and even meaning from knowing what is going on with their brain and health.

So how good are we at recognizing Alzheimer’s?

Not as good as we’d like to think. When a physician makes a diagnosis of Alzheimer’s, estimates compared with autopsies or less direct assessments of amyloid and tau (the proteins that misfold in Alzheimer’s), we are wrong somewhere between 10-35% of the time. Why is this? Good question. It may be an error due to over-confidence, and a kind of self-fulfilling prophecy. Knowing that Alzheimer’s is the most common cause of dementia, we may be more likely to just assume that dementia (meaning thinking changes getting in the way of independence), we may just jump to the assumption that dementia is due to Alzheimer’s, even when it’s not.