The timeline of Alzheimer’s Disease
Subtitle: for those who clicked the link
What follows is the difficult science of predicting your unique journey with Alzheimer’s disease. The number one rule, is that everyone is different.
However, there are some general patterns about how quickly things change for certain “archetypes” of people, which can give you a clue to how quickly you might move between "the first few years" (early stage), "the next few years after that" (moderate stage), and “the final years” (end-stage disease).
This article is a continuation of “Looking to the future with Alzheimer’s”.
It will provide you with very specific timelines and very frank statements about death from Alzheimer’s disease.
If you are not prepared to read this kind of information, please stop here and go back to the previous article.
…
As well, please know that I do not hold a crystal ball, and predictions are difficult.
I'm taking a leap of faith with you, using my years of experience working with patients and families and putting down the best estimates based on this experience and what is known from research studies, to guide your planning.
If you don’t want to know, go back to the article we were on together about the overall story of Alzheimer’s disease.
However, if you continue, what follows will give you more control over your life by giving you all the information you need to make fully informed choices.
…
Still in?
Okay. Let's break it down into two typical "archetypes" of Alzheimer's Disease - Type 1 and Type 2, which are not categories that exist outside the OG Medicine universe - I just find them helpful for explaining things.
Type 1: You’re otherwise pretty healthy
Other than this new diagnosis of Alzheimer’s disease, you are pretty healthy. You only take a few medications, and are reasonably physically fit (i.e. you can physically do what you need to do on most days). You don’t drink very much, smoke, or use other drugs.
Years left: There is a good chance you’ll live a long time with Alzheimer’s disease - up to 20 years at the most, but more likely in the range of 8 - 12 years. This varies by how young you are when you’re diagnosed.
If you’re diagnosed in your 90’s you’re more likely to live about 3-5 years with the disease.
How quickly things change: The number of years you spend in each stage will vary, but the moderate stage (what we’re about to get into in the next section of the “Looking to the future with Alzheimer’s” article) tends to be the longest.
For example, let’s say you live 8 years with Alzheimer’s disease. That might look like 2-3 years in the early stages, 4 years in the moderate stages, and 1-2 years in the end stages.
Again, the exact timeline will vary for everyone, but most people will follow this general trend. You might be usual, or you might be an outlier.
If you’re an outlier (i.e. rare) you can either change more quickly or more slowly.
More quickly - this could look like moving through the early stages in 1-2 years, moderate 2-3 years, and end stage 6 month - 1 year.
If you go from onset of symptoms (i.e. getting a bit more forgetful and are diagnosed with pre-dementia) to moderate disease within a year, you should see your doctor urgently and ask to see a specialist. You might have what we call “rapidly progressive dementia” - which is not always caused by Alzheimer’s disease. Within this category there are one or two things that are reversible.
However, most people that are referred to me for this condition actually did have symptoms for longer than a year - they were just chalked up to “old age” by friends and family. As a result, we don’t find anything reversible, and they continue on the course of Alzheimer’s disease.
The other group that tends to change more quickly are those diagnosed at an older age (i.e. 90+ years of age).
More slowly - this could look like spending 4-5 years in the early stages, then progressing into moderate disease for 4-8 years, followed by a longer time in end-stages 2-4 years.
If this happens for you, you might have a disease that is indistinguishable from Alzheimer’s disease but changes much more slowly. This disease is called Limbic Predominant Age-Related TDP-43 Encephalopathy, or LATE for short. It is much more rare than Alzheimer’s disease. It tends to be diagnosed in those > 80 years old, and there are no cures for this disease either (there are no cures for any dementia in existence at this time).
With our current tests, there is no way for your doctor to know if it is Alzheimer’s or LATE on the day you are diagnosed (at least in Canada). Even if a test becomes available, it will likely not be covered by insurance because it doesn’t change what the medical system will do for you - although I would argue it would certainly change how you go home and live with the disease knowing you have more or less years.
There is no way for me to predict which course you will be - usual, quick, or slow. However, as time passes, we can get a sense based on how things have changed already - past predicts future.
If you’re moving slowly…. you might be a slow disease.
If you’re going through the stages at the common rate (2-3 years of early disease then moving into moderate) you might be the usual case.
If you’re changing quickly - see your doctor - and know you might reach the end stages within a few years.
Why it matters: knowing how much time you might have left is devastating, but also powerful. Tell your friends. Tell your family. Make sure you make the most of your time together.
As well, you can start to map out a plan for the future
What is most important to you?
What do you want to do with your time?
Where will you move when the time comes?
How much money will you need to pay for the increased healthcare costs dementia will bring?
These are incredibly important questions, that can be better answered when you have a sense of the timeline.
How you die: Since you are relatively healthy, unless some other health condition comes up - like cancer, a massive stroke, heart attack, or severe infection - there isn't anything else that will end your life.
You will die from end-stage Alzheimer’s disease.
In the section on “the final years”, I’ll explain what this will look like. The majority of people die from swallowing difficulties that cause recurrent pneumonias.
This is important to know, because at some point, you might choose (through your power of attorney speaking on your behalf), to not treat a life-limiting disease that comes up, once your quality of life is no longer acceptable to you.
This would allow you control the number of years you spend in end-stage disease (or even entering the end-stages, if you decide to not treat something while still in moderate stage), without having to pursue things like Medical Assistance in Dying (MAID), which is legal in Canada and some states in the USA.
We’ll go over this in more detail in the section on “final years” (linked here if you want to jump back now).
Type 2: You have many other diseases
People that I see in this category tend to have a medical history that includes previous heart attacks, strokes, high blood pressure, diabetes, high cholesterol, chronic heart failure, chronic obstructive lung disease, obstructive sleep apnea, alcohol use, smoking, and more.
Years left: knowing what and when is much harder to predict for you. Given your medical issues, a life-ending illness could come up at any time - this could be a massive stroke, heart attack, sepsis, surgical emergency, or new cancer.
However, if you do not die from one of these things, you will follow the same timeline for Alzheimer’s disease that I outlined above, with an average of 8-12 years.
How quickly things change: like those in Type 1, most of your time with Alzheimer’s will be spent in the moderate stages.
However, you may decline more rapidly if you have flares of your other illnesses that require admission to hospital. Anyone with Alzheimer’s (Type 1 or Type 2) is prone to getting more confused when in hospital (something called delirium).
Sometimes that confusion never fully lifts, even after you get physically well enough to go home. This can lead to what looks like a “step-wise” decline in your memory/thinking and day-to-day function.
How you die: Because of your other diseases, you may not live long enough to get to the final stages of Alzheimer’s disease. You are more likely to die from one of your other diseases or a complication of them.
For example, you may die from a heart attack when experiencing only early Alzheimer’s disease, at which point you still remember most things and are still living on your own.
However, if you live into the moderate stages of the disease, you may be more likely to need more physical help - not just help with memory - at a much earlier stage.
For example, you might still know how to take a shower on your own, but you are too physically weak to do it without support from a loved one or personal support worker.
This means that you may need a lot of private and government-funded support for a longer time during your life with Alzheimer’s disease.
…
You did it! Good for you for being brave.
I will discuss the final stages of Alzheimer’s disease in more detail in the last section of the main article, and show you how you can still have control and independence for most of your life. I will give you the tools that you need to live and die on your own terms, regardless of stage.
No homework for this section; you've been courageous enough.
Now back to the core article on Alzheimer’s disease. Click Here.
Dr. Olivia Geen is an internist and geriatrician in Canada, working in a tertiary hospital serving over one million people. She also holds a masters in Translational Health Sciences from the University of Oxford and is widely published in over 10 academic journals.