Aging and Alzheimer Disease

Alireza Atri, MD, PhD: Lynn, what is the cognitive behavior functional trajectory that’s due to normal aging, as we understand it? And how’s that different in individuals with Alzheimer disease?

Lynn Shaughnessy, PsyD, ABPP/CN: First and foremost, there are certainly mild declines that come along with normal aging, but they are just that in nature—they are mild. There can be subtle changes in speed, or in one’s ability or capacity to learn. Maybe you’re not learning as much information, or maybe you’re having a little bit of difficulty retrieving that information. But you’re not losing that information, and you’re not having a drastic decline in your thinking. You’re not forgetting events, major events, or having trouble caring for yourself, for example.

I think there’s a common misconception that as we get older we’re going to have a drastic decline in memory and thinking, overall. But in reality, changes should be pretty subtle. And that’s in contrast to something like Alzheimer disease, for which one would typically have difficulty holding on to information and would be losing information, and eventually have declines to the point where they would have difficulty caring for themselves. But oftentimes, I’ll be speaking to a patient or a family member, and a lot gets attributed to older age in that: “Oh, well, you know, they can’t remember anything. They’re just old.” That’s not actually the case. That’s actually pathological aging as opposed to normal aging.

Alireza Atri, MD, PhD: Other than memory, are there other functions that can be destructed in Alzheimer disease as symptoms? We’ll get into this more later on, but just as a bullet?

Lynn Shaughnessy, PsyD, ABPP/CN: Of course. Memory oftentimes is kind of the typical first symptom, but people oftentimes have changes and trouble with word finding and trouble coming up with the right word, which can be seen in normal aging but not to the extent that you would expect in the Alzheimer disease process. And we’ll talk about atypical presentations of Alzheimer disease a little bit later.

Alireza Atri, MD, PhD: Years earlier, when I was learning about these things, there was a contrast made between sort of fluid intelligence, which is that processing ability of learning new things quickly, manipulating ideas, and processing them, and crystallized intelligence, which is our experiences, and wisdom, and those things that tend to be much more crystallized.

Lynn Shaughnessy, PsyD, ABPP/CN: Sure. Something like your vocabulary, or things like that tend to be more crystallized and less vulnerable to change over time. Whereas, different areas of functioning, like memory, are a little bit more susceptible.

Alireza Atri, MD, PhD: Is that one of the reasons, for example, that individuals with Alzheimer disease can go many years before being detected? Because they have language skills, in some ways, that are preserved much more, or social skills?

Lynn Shaughnessy, PsyD, ABPP/CN: Yes.

Alireza Atri, MD, PhD: And yet they can have incredible difficulty with cognitive functioning in their own home, and in memory?

Lynn Shaughnessy, PsyD, ABPP/CN: Yes, absolutely. And that can get unmasked later on.

Marc E. Agronin, MD: It helps clinically, too, because it gives individuals some strengths that they can really build upon. We get very focused on their deficits, but we also have to keep in mind that there might be social skills, or vocabulary, or some of these more crystallized areas that can really make all the difference in terms of keeping someone functional and engaged socially.

Alireza Atri, MD, PhD: Absolutely.

Transcript edited for clarity.