Both our internal information people and the local press are
getting very excited because some Karolinska people have made some
pretty good progress towards developing a test that will predict
dementia 20 years ahead. [Press
release, with links to the original article] It's cool science, no
doubt about it, but I can't help wondering, would you want to
take a test at the age of 50 that might predict that you had a high
chance of being senile by the time you were 70? I guess it's the same
problem as with any predictive medical testing: in the absence of a
cure or even sensible prevention, what's the point of knowing?
I think it's the timescale that bothers me, in part; I don't have the
same objection to, say, cervical smears which tell me whether I might
be at risk for cancer in the coming few years. That allows me to do
something about it in terms of possibly readjusting my life plans. But
I can't plan on the basis of some terrible thing that might happen in
20 years' time; I'd just have to live with the knowledge that this was
likely to happen to me, which I don't think would be good
It's true that almost everybody expects to be mortal (the exceptions
are a few religious people and a few quasi-religious geeks who think
the Singularity is going to cure death). So you always have to run
your life on the basis that you have a few decades at best and
possibly even less. But I'd still rather not know the probable time
and manner of my demise more than a few years in advance, I think.
In non-morbid news: Stockholm is full of magicians and flamboyantly
gay people with rainbow banners at the moment. I find this very cool,
it's a bit like living in the Paul Gallico novel The man who was
There are a couple of legitimate uses, I think. Many people don't save enough for a normal retirement, let alone one that requires expensive in-home/residential care like dementia; this might be a wake-up call to such people. (Of course, people who are so disorganized about retirement are likely to fail to take the test, too.)
I have also heard the opinion expressed by some people that it would be better to be dead than to be senile - they can then make suitable arrangements in advance, to be put into place when they notice the onset of senility.
The idea that the existence of such a test (assuming that it's developed to the point where it's commonly available) might encourage people to make more financial provisions for old age is definitely a possible application. Though previous examples tend to suggest that at least a proportion of people, finding out they have something scary in the future, decide to live as complete hedonists and stop being sensible at all, because they're screwed anyway.
I am really, really wary of the "better dead than" types of opinions. Partly because a lot of people describe the kind of fate which would cause them to prefer death and end up talking about aspects of my brother's situation. I know intellectually that noboday actually wants to kill my brother, but emotionally I find it very hard to assess such arguments in a neutral way. I do feel like there's sometimes an undercurrent of "it would be better for society if people like that conveniently preferred to be dead, not of course that anyone would ever advocate murdering a person who was very expensive to care for, but if it were entirely voluntary..." Sometimes, people who make those kinds of arguments are (unconcsiously) propagating the meme that death is better, more than they are actually imagining themselves in that situation.
I also don't think that, as society is at the moment, it's all that possible to "make arrangements" to die in order to forestall a terrible outcome. Even people who are currently in terrible pain face a lot of obstacles in getting help to end their lives.
I don't think that most people really realise that they're mortal*. It could be a really life affirming wake up call of 'You've got two decades left; don't waste them.' There may also be people who have a history of dementia in the family and so already think their going to get it and the test will either just confirm their suspicions or give them relief from the expectation that it will happen to them.
*It reminds me of an anecdote from an HIV positive comedian who said that he was doing stand up and said "I'm HIV positive. Do you know what that means?" and someone yelled "Yeah, you're gonna die." to which he replied "And you're not? Ladies and gentlemen we have Jesus at the back of the audience!"
That's a really good point: many people don't really believe in their own mortality on a level that affects them emotionally. The trouble is though that 20 years is too long. I came across some research into the psychological aspects of cancer treatment which concluded that, if you tell someone that they have an evens chance of dying within 5 years (obviously you express it less brutally than that!), it affects them, but if you tell them that they have an evens chance of dying within 10 years, it has no measurable effect. Of course, that's a statistical conclusion; some individual people may feel an emotional connection with their future selves more than 5 years ahead.
To be honest, any given 50-year-old has a significant probability of being dead within 20-30 years, so knowing that they will likely be senile in their seventies doesn't really change the situation all that much in terms of how they view their future and how much time they have left.
Well, as the article itself points out, if you know you're at risk, you can start taking medicine earlier and delay the onset of the disease.
I read the other week about a whole family, who had a genetic predisposition to stomach cancer in their fifties, who all had their stomachs removed as a prophylactic measure. That's a hell of a decision to take—rule out eating normally for the rest of your life against the (likely) probability of stomach cancer years if not decades in the future.
That's assuming there is some medicine one can usefully take, yes. I'm not against all predictive medical testing in a blanket way. I guess in this case the main intervention available would be blood-pressure controlling medications (and possibly life-style changes); those are not sufficiently safe you'd want everybody on them just as precaution.
The stomach cancer example seems a bit odd; surely if you have a genetic tendency to stomach cancer in your 50s, you're not going to gain much by having your stomach removed as a child or in your 20s; why not continue to live a normal life (though presumably having regular checkups for any possibly cancerous changes) until your mid forties or the first abnormal biopsy?
There are steps being made towards prevention of dementia and suchlike - supplements that boost chemicals thought to improve memory retention and suchlike. The problem is that no-one knows the long term effects; thus it might be sensible for those with high risk to take the supplements.
Are there? Drugs that help to prevent dementia that are currently in development? I didn't know that, and my comment was based on assuming there are no such drugs. But certainly if that is the case it makes the test a lot more useful. And of course it's useful to develop the test so that it will be available if someone does come up with a possibly unsafe preventative drug! That's part of what I meant by saying it was good science.
A few decades or less strikes me a tad optimistic - living in a place surrounded by crazy drivers has made me reconsider my projected life expectancy. On the plus side, its a near religious experience to have just avoided being flattened by another vehicle....
Eeek, you're scaring me. Do take care of yourself. I do remember when you suddenly got a lot more careful about London roads because you had a family to provide for. But yeah, car accidents are the major example of totally unforseeable causes of death; the 50-year-old who is stressed about going senile might get run over tomorrow and all the worrying and medical testing would be for nothing.
Did your recent spell in hospital make you feel more mortal? I know I felt a lot more aware that bad things might happen to me after spending time in a hospital, (though in my case it wasn't me needing treatment but just visiting my brother after his accident in 2002).
My mother watched both her parents die of Alzheimer's disease. It's not clear to me how much that overlaps with the "dementia" in the article. As soon as there was a test for the genetic marker for early-onset Alzheimer's, my mother wanted to have it. She lives alone, and she's terribly anxious. When a woman in her fifties (who is tempermentally inclined to obsessive worries) starts to become a bit forgetful, how can she tell if it's just normal forgetfulness or the beginnings of something more serious? They tell everyone, "Forgeting where your keys are is normal. Forgeting what keys are for is Alzheimer's." But my mother's house is full of things that *I* couldn't tell you what they were for -- it's not that I have dementia, it's that I'm the wrong kind of geek.
I'm really not very well up on dementia; I should read more about it. I didn't know that there was an identified genetic marker for Alzheimer's. In a way I can much more strongly see the point of taking the test, if you have a family history and want to know if you carry the gene, because that gives you definite enough information to work on and the possibility of reassurance if you don't have it, when you're likely to be worried anyway.
The test I linked to seems to be mostly a lifestyle questionnaire, with little (or even no, I skimmed a bit) biochemical component. So all it would do is tell someone like your mother what she knew anyway: she's at high risk due to her family history. I agree with you that it's a bit odd to talk about dementia in that vague, general way; everyone will assume Alzheimer's but I'm pretty sure they would have said that if they meant it.
Worrying about possible dementia from late middle age onwards is to some extent unavoidable. I'm not sure whether making that worry worse is desirable or not. There's an advantage in that you're more likely to get intervention early if you are watching for symptoms, but the level of help currently available is barely even at the level of damage limitation. So I'm not sure that balances the disadvantage of having to spend your life in a state of paranoia about losing your mind. For people who have lost a parent, and to a lesser but probably still significant extent any older loved one, to that disease, well, it really only depends on temperament whether they're going to be scared anyway. Tests, even negative ones, probably won't help much with that.
Long-term planning is great; you may well be an outlier in terms of being able to see yourself 20 years ahead. But what kind of planning would you do, if you knew you had a higher than average probability of developing dementia in the next 20 years? (That's a question, not a statement of disbelief.)
I'm with lavendersparkle. I think it really could be a stimulus for living and decision making. A very concrete justification for really working out what 'living' means and doing it, as much as a predictor of doom and warning to take action now.
The press release is pretty vague on the detail about the predictive power and accuracy of the risk score though. While I'd want to know myself, I'd want to know with some certainty. Being told that I had 5% chance of developing some form of vascularly-caused dementia wouldn't be especially useful (and what is the general chance anyway I wonder?), but being told there was an 80% chance I'd lose my marbles due to a string of CVAs would be a different thing. I'd take the Sword of Damocles then, rather than not know and not be able to plan.
Thanks for the link; very interesting to know that there is possibly a drug for slowing the onset of Alzheimer's on the horizon.
You're quite right about needing more statistical information to be able to assess whether the test is useful. That's always the way with any attempt at predicting anything, though; you can put numbers on it but probably a sadly small proportion of the test subjects are going to have enough grasp of risk and statistics to make any sense out of the numbers. And even for those who do understand risk, it's hard to set the threshold for what level of increased risk is actually useful information.
I'll ask you the same question I asked leora; if you did find out that you were at risk (for some meaningful value of "at risk"), what kind of planning would you be doing? I can see a lot of merit in the idea of really working out what 'living' means and doing it, but I'm inclined to think everybody should do that anyway, on the grounds that we're all mortal.
Predictive tests would be wonderful if they gave 100% certainty but, in reality, the results give anything from a 90% probability to 'double the risk in the general population' of a very rare condition.
At 90%, the test result is usable information: I'd start making arrangements: nursing homes, do-not-resuscitate contracts, and a veto on pension plans that involve annuities or long maturities.
At 50%, the test result is a curse because I can't use the information. At least, not at current levels of medical knowledge for dementia. Heart disease would be a different matter, even at a 20% risk forecast - I'd make radical changes to my lifestyle, rather than the general preference for a healthy diet and exercise that is my current lifestyle strategy, and I'd get regular check-ups.
Of course, at even 2%, the information would be used for me by insurance companies. O rather, against me.
Yes, good point about the perils of only knowing altered probabilities. That's pretty much all you get with any medical test, though, as you know.
I like the way you've come up with practical suggestions for how you would react knowing that you might be senile in 20 years' time. Actually looking into nursing homes versus making investments that gamble on your living longer than average, good thoughts.
I think this test is a useful thing for the world in general, because the scientific / medical community are making real progress into the study of dementia. People have mentioned preventative drugs and even one which delays the progress of Alzheimer's, and I do think there's a reasonable chance that we will get to the point where there are lifestyle and pharmaceutical things you can do about a nasty flag on a test result. At that point, the test will become useful; right now it's a case of, would you really want to know that something horrible is going to happen to you when you can't do anything sensible to prevent it?
I'm a lot less worried about insurance companies using medical tests than people in general seem to be. It's one area where I largely trust the free market to sort it out. (Of course, this depends on there being such a thing as the NHS and social security generally, so that even uninsurable people have some kind of backup. The abominable situation in the US is a different scale of problem altogether.)
I agree that the press being excited is a bit barking up the wrong tree. Though if I know there's an easy test, it'd be hard to not take it, even if in theory I'd rather not know.
What surprised me most is it wasn't biochemical, but about your current body and lifestyle: does that mean your sedentriness etc contributes to dementia? Or comes from the same cause? *That* seems a very useful observation, for potentially finding out how to prevent it.
You're right, if it's true that lifestyle and diet factors like these have a big effect on probability of dementia, that's really interesting. But do see adrian_turtle's comment on this. I don't know if her cynicism is appropriate in this case, but I do know that the medical profession (in the most general sense) is bedevilled by the kind of attitude she mentions. So I would be very sad, but not at all surprised, if she's right :-(