Ryan, thank you again. Your concerns are my concerns, I am grateful to you for them.
And I apologise. You have been talking to a raving lunatic, by the ICD10 diagnostic criteria as applied by my attorney and myself. See the exchange with buybuydandavis for details. I am apparently recovered now, in the opinion of one who should know.
I am painfully aware that I have reasoned myself into a place where I prove too much.
I am in the position of a philosopher who started out with a little detail, and is now claiming ‘It is at least marginally possible that here is the light and the sacred cup’. Knowing that he is wrong.
I was carefully and expensively trained to speak with certainty when and only when I was certain. The Lord knows I was never very good at it.
I have used plausible reasoning where I only trust classical logic.
I am forced to seek the Grail.
But I cannot shake the suspicion that I might be right. And I know that my hopeless hardware will not let me find the reason why I am wrong.
1 - It has never been the case previously that almost all unexplained human ailments have shared a single simple explanation
It has. The germ theory.
I am claiming that the great killers of the past may have left their shadows in our genes, and those shadows still plague us today.
I am claiming that the great changes we have made in our environment may have hurt us worse than we know.
Here I stand, naked to the world. Afraid. I can do no other in good conscience. I do not believe my own conclusion.
I hope that when I am shown to be wrong, I can retreat with no more than huge embarrassment, resolving to fail better next time.
And it all depends on the TSH test. If I am wrong about that, I am just wrong.
If the TSH test is flawed, then all our statistics are confounded, and we have some thinking to do.
Still Crocker’s Rules though! Let this cup pass from me!
OK, type 2 diabetics, suffering from a mysterious condition that prevents insulin (an endocrine hormone) acting on their cells, can achieve very good blood sugar control by overwhelming the resistance with exogenous insulin.
And yet they still suffer horrible complications. Which look awfully like hypothyroidism.
The simplest explanation is that this mysterious condition is interfering with other endocrine hormones as well.
Desiccated thyroid, containing excessive T3, will overwhelm the hormone resistance, and clear up the complications of diabetes.
T4 alone will not change the amount of T3 in the blood significantly, since it is subject to the body’s T4->T3 conversion mechanism, which defends T3 levels.
Therefore T4 will not help diabetics, but T4/T3 combinations will.
Broda Barnes observed this empirically in the sixties. I predicted it independently before I read his book.
Find a diabetic colleague, and explain this to him. I predict that he will suddenly take the idea very seriously indeed.
1 - It has never been the case previously that almost all unexplained human ailments have shared a single simple explanation
It has. The germ theory.
While I am very much not a medical professional, I do know that, while germs cause a lot of trouble, there are nonetheless quite a variety of things that can go wrong that have nothing to do with germs. There are even a lot of things that can go wrong that have nothing to do with the closely-related viruses.
Examples include:
Physical trauma (e.g. broken legs)
Nutritional deficiencies
Genetic diseases (sickle-cell anemia?)
Hormonal imbalances
Cancer (I think a growth is different from a germ, right?)
Asphyxiation and/or drowning
And I think it’s possible to cause trouble for yourself by drinking too much water as well—it has to be seriously too much—and that’s also not due to germs...
I know you’re teasing, but physical trauma and drowning aren’t unexplained, sickle-cell anaemia is very much explained by germ theory (malaria defense), controlling nutrition and energy usage is probably exactly what the thyroid system’s for in adults, hormonal imbalances are what I’m talking about, and OK, I’ll give you cancer. For now.
In fact I think I’m trying to add a coda to the germ theory. One reason that ancient control systems would just spontaneously go horribly wrong is if they were in a continuous state of desperate patching and hacking to deal with an intelligent and adaptive enemy. And pathogen evolution is just that.
That’s why we see in living systems a combination of beautiful engineering and idiotic kludge. Like a BMW with a tin can lid riveted on one side. The explanation is likely to do with bullets.
Therefore we expect infectious cause for this sort of horror. But we don’t find it. Where is it? In the past. Today’s fuckups are yesterday’s hastily constructed defenses.
Not of course to forget the environment. If we’ve got a hideously complicated and sensitive chemical control system that’s been tested to death really well in the presence of all the usual chemicals, and suddenly we start adding new chemicals, what then?
Notice that a lot of cancers are caused by novel chemicals, and a lot of them are caused by viruses.
Presumably all the viruses and bacteria and fungi and cancer cells are themselves generating novel chemicals in order to screw the system up so it can’t kill them.
One thing I don’t claim is vitamin deficiencies. But they fit into Cochran’s framework nicely.
And I’ll give you that if you deliberately drink far too much water even though you’d really like to stop and then it kills you, you’ve got a genuine ‘somatoform’ disorder.
Except even then. That sounds like the sort of thing people do on drugs. I wonder how those drugs act on the mind?
Sickle-cell anemia may have been a bad choice. It was supposed to be an example of genetic factors causing trouble—which can happen even in the complete absence of germs, since random mutations are rare but possible. (The fact that one particular genetic factor is partially successful because it provides a higher resistance to certain germs is somewhat beside the point).
Absolutely, a famous example is Queen Victoria’s mutation that caused haemophilia in some of her male descendants. The queen really does seem to have been the mutant, and it was just a rotten bit of luck!
What needs explanation is how a harmful random mutation can spread to a significant proportion of the population. One way that can happen is if it’s actually also a defence against something, and another is if the heterozygote version is good, but the homozygote is harmful.
With a large fitness advantage, mutations can spread quickly! Consider a lightning plague like the black death. It wiped out a third of the population of Europe in a couple of years, and then simmered and flared for centuries. A ‘harmful’ gene that defended against that would have had a whale of a time, and you’d expect to see it in all Europeans.
But if it’s really harmful, you’d expect that over the last 600 years, better defenses might have evolved, and the previous defence might start evolving back out.
About 500 years ago, all the old world plagues were introduced to the Americas at once, and they literally decimated the native population. I don’t know if there are any ‘pureblood’ native americans left, but if there are, their genes should be a mass of defensive scars.
What needs explanation is how a harmful random mutation can spread to a significant proportion of the population.
Easy.
The harm is easily avoided. For example, an allergy-against-bananas gene might not affect one’s reproductive fitness at all in the modern world—one merely needs to avoid bananas.
The “harm” is to the society, not to the individual. For example, a mutation (in males) that causes all children born to be male will not harm the person carrying the gene, but will end up with fewer total greeding pairs in subsequent generations.
A guy with the harmful mutation just happens to have a lot of wealth of political power—and takes a few dozen wives.
(1) Sure, but that sort of thing will just random-walk, it would take ages to go from one mutation to 50% of the population. It has almost no fitness effect. It will probably get gambler’s-ruined out.
(2) Absolutely, and we see those things in animals. You can evolve to extinction. In the particular case of a male-causing gene, I think it would have to stabilize very low (because the more successful it is the more harmful it is to the carrier) , but you can certainly imagine (and find) driving genes that just become rapidly prevalent and wipe out the species.
(3) Yes, but that’s just the random walk walking. It has to get very lucky to become prevalent, and if it’s actively harmful, it won’t get that lucky, and that will kill it off eventually.
In general, harmful mutations will die out. In order to spread to a significant proportion of the population, yes, a random mutation has to be lucky. It has to random-walk in a very rare way, and it is still more likely than not going to hit the gambler’s ruin and be eventually eliminated from the population, even if it first spreads to 99% of said population (an extremely unlikely event).
But the thing about random-walking is that it is random. One wouldn’t bet on a given harmful mutation spreading fast (not if one wanted to win the bet)… but if there are a million harmful mutations, then one of them could reasonably be expected to have one-in-a-million luck.
I think we’re pretty much on the same page. But have you actually calculated the odds? One in a million is no big deal. Twenty half-chances.
I must say I haven’t, and I don’t know how to (especially since it’s all screwed up by genes moving around and getting passed on together, and I don’t understand the first thing about all that). But it feels more like ‘thermodynamic entropy’ than ‘winning the lottery’.
Also remember that nothing is perfectly neutral. Even the banana man might get fed banana-cake by a dastardly enemy.
No, I haven’t actually calculated the odds. I wouldn’t really have much of an idea how. (I could probably work it out on a basis of—if a gene has x% chance of preventing descendants as compared to not having that gene and a y% chance of being passed on to any descendants—and then do some overly-simplified calculations from the values of x and y—but I haven’t, yet.)
Also remember that nothing is perfectly neutral. Even the banana man might get fed banana-cake by a dastardly enemy.
True, but his problem there isn’t the banana gene. His problem there is that he has a dastardly enemy. If he didn’t have the banana gene, the dastardly enemy could simply feed him arsenic cake instead, or just shoot him.
The official name of a mutation winning despite having no selection benefit is genetic drift. When I had genetics lessons in university the concept that was taught was that a significant amount of our genetic changes are due to gene drift but there’s no exact way to quantify how many.
Furthermore some genes aren’t stable and can easily mutate. Evolution doesn’t succeed in bringing color blindness to zero despite it being no useful mutation.
Yes, an obvious one is the inability to manufacture Vitamin C. Universal in great apes, including us, but every other animal and plant can do it, except guinea pigs.
I imagine that at some point our ancestors lived in a vitamin C rich environment, so losing this was no immediate handicap. But even then, the random drift should have taken ages. Is there some reason why losing this pathway would be a benefit?
Same for colour-blindness. Is it drifting, or is it actually good for something in an environment where it does no harm? (These poor children, none of them will ever be commercial pilots or qualified electricians....)
“Literally decimated” would have reduced the population by 10%. Some Native American groups were hit much harder than that. (I think the “mound builders” in what is now the southeastern US may have actually disappeared completely.)
Minus the “literally”, though, the word “decimated” in current English uses would include much more severe population declines. I’m just being unnecessarily pedantic.
Spectacular pedantry is sort of where I’m coming from here, though. And actually literally can be used metaphorically too, and has been for some centuries. I’m confidently expecting this to be the most controversial assertion in this entire discussion, so you can go look for your own references. [Openly trolling now]
According to Wikipedia, yes, the Norse made it to continental North America in pre-Columbian times and made multiple voyages there to obtain natural resources (primarily fur and timber), but did not establish any permanent colonies (perhaps due to hostile relations with the native Americans (which the Norse called the Skrælings)).
The Wikipedia article mentions that a Norwegian coin from King Olaf Kyrre’s reign (1067–1093) was allegedly found in a Native American archaeological site in the state of Maine, but does not mention any definitive evidence that the Norse made it to the mainland.
Tuberculosis keeps coming up. It was deadly and recent and widespread, and it’s implicated in the ‘plausible mechanism’ paper, and in the one about rheumatoid arthritis, and the other day I met an old friend with bladder cancer. Apparently he’s having tuberculosis drugs injected to try to kill it. No one knows why, but it works about 30% of the time!
It would be way interesting if someone had statistics for ancient diseases and statistics for modern unexplained diseases. I’ve no idea what to predict, but I bet it’s not ‘no correlation’.
Yes, I based the entire second post on it, and referenced it. But thanks, that would have been really useful!
I just emailed the address on the paper (paul ewald) to see what they thought of it. But no reply. If anyone knows one of them could you tell them there’s someone wrong on the internet?
I know you’re teasing, but physical trauma and drowning aren’t unexplained
Physical trauma doesn’t have to be explained, it’s an explanation. In cases like broken legs it’s a pretty straightforward explanation. In other cases like depression, it get’s more complicated.
An explanation is a chain of causal links, where each one is verified under interventions. If I hit you with a sledgehammer, your leg will break, and we know why, and it’s not that my anger causes ‘stress’, and that breaks your leg by magic stress-property, because I’m stressed too, and yet my leg never breaks.
A vague correlation is not an explanation. It’s a sign that you should look for one. Sure if I attacked you with a sledgehammer, you might get depressed. But why?
Sure if I attacked you with a sledgehammer, you might get depressed. But why?
Depression in patients with acute traumatic brain injury :
Major depression occurs in about one-quarter of patients after traumatic brain injury. This is the same frequency as in other major disorders such as stroke. Major depression appears to be provoked by one or more factors that include poor premorbid social functioning and previous psychiatric disorder or injury to certain critical brain locations.
Depression among older adults after traumatic brain injury: a national analysis.: TBI significantly increased the risk of depression among older adults, especially among men and those discharged to a skilled nursing facility. Results from this study will help increase awareness of the risk of depression post-TBI among older adults.
It’s plausible that the trauma kills neurons and thus creates depression. It’s also possible that some fascia tenses up and produces problems. It’s possible that it produces Sensor Motor Amnesia. It’s possible that it creates problematic inflammation.
There are a lot of plausible mechanisms to choose from.
Agreed. Thanks. It was more a sort of philosophical point about the nature of explanation. We might be able to tell which of these counted as an explanation by intervening later on in the proposed causal chain and seeing if the same results obtain.
As far as the philosophy goes, for most successful interventions in health care we don’t really know how they work.
Depression usually comes along with increased inflamation of the gut. Depression medicine that’s intented to target the brain because of chemical imbalance, also hit’s targets in the gut.
Does that mean I’m certain that those drugs fight depression by having positive effect on the gut? No, I’m not certain of that, but it’s an open possibility.
“Explanations” in general aren’t good at predicting outcomes for drugs. That way so many clinical trials fail. The only way that seems to work is to gather empiric evidence for treatments. That way you know whether the treatment works but not why it works.
Ryan, thank you again. Your concerns are my concerns, I am grateful to you for them.
And I apologise. You have been talking to a raving lunatic, by the ICD10 diagnostic criteria as applied by my attorney and myself. See the exchange with buybuydandavis for details. I am apparently recovered now, in the opinion of one who should know.
I am painfully aware that I have reasoned myself into a place where I prove too much.
I am in the position of a philosopher who started out with a little detail, and is now claiming ‘It is at least marginally possible that here is the light and the sacred cup’. Knowing that he is wrong.
I was carefully and expensively trained to speak with certainty when and only when I was certain. The Lord knows I was never very good at it.
I have used plausible reasoning where I only trust classical logic.
I am forced to seek the Grail.
But I cannot shake the suspicion that I might be right. And I know that my hopeless hardware will not let me find the reason why I am wrong.
It has. The germ theory.
I am claiming that the great killers of the past may have left their shadows in our genes, and those shadows still plague us today.
I am claiming that the great changes we have made in our environment may have hurt us worse than we know.
Here I stand, naked to the world. Afraid. I can do no other in good conscience. I do not believe my own conclusion.
I hope that when I am shown to be wrong, I can retreat with no more than huge embarrassment, resolving to fail better next time.
And it all depends on the TSH test. If I am wrong about that, I am just wrong.
If the TSH test is flawed, then all our statistics are confounded, and we have some thinking to do.
Still Crocker’s Rules though! Let this cup pass from me!
Forget about being proved wrong and facing huge embarassment.
Short-circuit that by getting some background domain knowledge then making claims that in light of that knowledge are reasonable.
OK, type 2 diabetics, suffering from a mysterious condition that prevents insulin (an endocrine hormone) acting on their cells, can achieve very good blood sugar control by overwhelming the resistance with exogenous insulin.
And yet they still suffer horrible complications. Which look awfully like hypothyroidism.
The simplest explanation is that this mysterious condition is interfering with other endocrine hormones as well.
Desiccated thyroid, containing excessive T3, will overwhelm the hormone resistance, and clear up the complications of diabetes.
T4 alone will not change the amount of T3 in the blood significantly, since it is subject to the body’s T4->T3 conversion mechanism, which defends T3 levels.
Therefore T4 will not help diabetics, but T4/T3 combinations will.
Broda Barnes observed this empirically in the sixties. I predicted it independently before I read his book.
Find a diabetic colleague, and explain this to him. I predict that he will suddenly take the idea very seriously indeed.
While I am very much not a medical professional, I do know that, while germs cause a lot of trouble, there are nonetheless quite a variety of things that can go wrong that have nothing to do with germs. There are even a lot of things that can go wrong that have nothing to do with the closely-related viruses.
Examples include:
Physical trauma (e.g. broken legs)
Nutritional deficiencies
Genetic diseases (sickle-cell anemia?)
Hormonal imbalances
Cancer (I think a growth is different from a germ, right?)
Asphyxiation and/or drowning
And I think it’s possible to cause trouble for yourself by drinking too much water as well—it has to be seriously too much—and that’s also not due to germs...
I know you’re teasing, but physical trauma and drowning aren’t unexplained, sickle-cell anaemia is very much explained by germ theory (malaria defense), controlling nutrition and energy usage is probably exactly what the thyroid system’s for in adults, hormonal imbalances are what I’m talking about, and OK, I’ll give you cancer. For now.
In fact I think I’m trying to add a coda to the germ theory. One reason that ancient control systems would just spontaneously go horribly wrong is if they were in a continuous state of desperate patching and hacking to deal with an intelligent and adaptive enemy. And pathogen evolution is just that.
That’s why we see in living systems a combination of beautiful engineering and idiotic kludge. Like a BMW with a tin can lid riveted on one side. The explanation is likely to do with bullets.
Therefore we expect infectious cause for this sort of horror. But we don’t find it. Where is it? In the past. Today’s fuckups are yesterday’s hastily constructed defenses.
Not of course to forget the environment. If we’ve got a hideously complicated and sensitive chemical control system that’s been tested to death really well in the presence of all the usual chemicals, and suddenly we start adding new chemicals, what then?
Notice that a lot of cancers are caused by novel chemicals, and a lot of them are caused by viruses.
Presumably all the viruses and bacteria and fungi and cancer cells are themselves generating novel chemicals in order to screw the system up so it can’t kill them.
I’m not saying. I’m just saying....
Infectious cause, immune defence, recent environmental change, recent adaptation to environmental change.
The four horsemen of unexplained diseases.
One thing I don’t claim is vitamin deficiencies. But they fit into Cochran’s framework nicely.
And I’ll give you that if you deliberately drink far too much water even though you’d really like to stop and then it kills you, you’ve got a genuine ‘somatoform’ disorder.
Except even then. That sounds like the sort of thing people do on drugs. I wonder how those drugs act on the mind?
Sickle-cell anemia may have been a bad choice. It was supposed to be an example of genetic factors causing trouble—which can happen even in the complete absence of germs, since random mutations are rare but possible. (The fact that one particular genetic factor is partially successful because it provides a higher resistance to certain germs is somewhat beside the point).
Absolutely, a famous example is Queen Victoria’s mutation that caused haemophilia in some of her male descendants. The queen really does seem to have been the mutant, and it was just a rotten bit of luck!
What needs explanation is how a harmful random mutation can spread to a significant proportion of the population. One way that can happen is if it’s actually also a defence against something, and another is if the heterozygote version is good, but the homozygote is harmful.
With a large fitness advantage, mutations can spread quickly! Consider a lightning plague like the black death. It wiped out a third of the population of Europe in a couple of years, and then simmered and flared for centuries. A ‘harmful’ gene that defended against that would have had a whale of a time, and you’d expect to see it in all Europeans.
But if it’s really harmful, you’d expect that over the last 600 years, better defenses might have evolved, and the previous defence might start evolving back out.
About 500 years ago, all the old world plagues were introduced to the Americas at once, and they literally decimated the native population. I don’t know if there are any ‘pureblood’ native americans left, but if there are, their genes should be a mass of defensive scars.
Easy.
The harm is easily avoided. For example, an allergy-against-bananas gene might not affect one’s reproductive fitness at all in the modern world—one merely needs to avoid bananas.
The “harm” is to the society, not to the individual. For example, a mutation (in males) that causes all children born to be male will not harm the person carrying the gene, but will end up with fewer total greeding pairs in subsequent generations.
A guy with the harmful mutation just happens to have a lot of wealth of political power—and takes a few dozen wives.
(1) Sure, but that sort of thing will just random-walk, it would take ages to go from one mutation to 50% of the population. It has almost no fitness effect. It will probably get gambler’s-ruined out.
(2) Absolutely, and we see those things in animals. You can evolve to extinction. In the particular case of a male-causing gene, I think it would have to stabilize very low (because the more successful it is the more harmful it is to the carrier) , but you can certainly imagine (and find) driving genes that just become rapidly prevalent and wipe out the species.
(3) Yes, but that’s just the random walk walking. It has to get very lucky to become prevalent, and if it’s actively harmful, it won’t get that lucky, and that will kill it off eventually.
A mutation needs an edge to spread fast.
In general, harmful mutations will die out. In order to spread to a significant proportion of the population, yes, a random mutation has to be lucky. It has to random-walk in a very rare way, and it is still more likely than not going to hit the gambler’s ruin and be eventually eliminated from the population, even if it first spreads to 99% of said population (an extremely unlikely event).
But the thing about random-walking is that it is random. One wouldn’t bet on a given harmful mutation spreading fast (not if one wanted to win the bet)… but if there are a million harmful mutations, then one of them could reasonably be expected to have one-in-a-million luck.
I think we’re pretty much on the same page. But have you actually calculated the odds? One in a million is no big deal. Twenty half-chances.
I must say I haven’t, and I don’t know how to (especially since it’s all screwed up by genes moving around and getting passed on together, and I don’t understand the first thing about all that). But it feels more like ‘thermodynamic entropy’ than ‘winning the lottery’.
Also remember that nothing is perfectly neutral. Even the banana man might get fed banana-cake by a dastardly enemy.
No, I haven’t actually calculated the odds. I wouldn’t really have much of an idea how. (I could probably work it out on a basis of—if a gene has x% chance of preventing descendants as compared to not having that gene and a y% chance of being passed on to any descendants—and then do some overly-simplified calculations from the values of x and y—but I haven’t, yet.)
True, but his problem there isn’t the banana gene. His problem there is that he has a dastardly enemy. If he didn’t have the banana gene, the dastardly enemy could simply feed him arsenic cake instead, or just shoot him.
The official name of a mutation winning despite having no selection benefit is genetic drift. When I had genetics lessons in university the concept that was taught was that a significant amount of our genetic changes are due to gene drift but there’s no exact way to quantify how many.
Furthermore some genes aren’t stable and can easily mutate. Evolution doesn’t succeed in bringing color blindness to zero despite it being no useful mutation.
Yes, an obvious one is the inability to manufacture Vitamin C. Universal in great apes, including us, but every other animal and plant can do it, except guinea pigs.
I imagine that at some point our ancestors lived in a vitamin C rich environment, so losing this was no immediate handicap. But even then, the random drift should have taken ages. Is there some reason why losing this pathway would be a benefit?
Same for colour-blindness. Is it drifting, or is it actually good for something in an environment where it does no harm? (These poor children, none of them will ever be commercial pilots or qualified electricians....)
“Literally decimated” would have reduced the population by 10%. Some Native American groups were hit much harder than that. (I think the “mound builders” in what is now the southeastern US may have actually disappeared completely.)
Accepted. I have managed to use decimated in the wrong way. Sorry.
Minus the “literally”, though, the word “decimated” in current English uses would include much more severe population declines. I’m just being unnecessarily pedantic.
Spectacular pedantry is sort of where I’m coming from here, though. And actually literally can be used metaphorically too, and has been for some centuries. I’m confidently expecting this to be the most controversial assertion in this entire discussion, so you can go look for your own references. [Openly trolling now]
In fact, how did any of them live through that? Did the vikings take some diseases and some genes over with them early doors?
Did the Vikings ever get out of Newfoundland? Is there any evidence they made it to the mainland?
According to Wikipedia, yes, the Norse made it to continental North America in pre-Columbian times and made multiple voyages there to obtain natural resources (primarily fur and timber), but did not establish any permanent colonies (perhaps due to hostile relations with the native Americans (which the Norse called the Skrælings)).
I asked about the mainland. The Vikings made it to Newfoundland, certainly, but Newfoundland is an island.
The Wikipedia article mentions that a Norwegian coin from King Olaf Kyrre’s reign (1067–1093) was allegedly found in a Native American archaeological site in the state of Maine, but does not mention any definitive evidence that the Norse made it to the mainland.
Yes, I know. That’s why I asked :-/
I have no clue. Is there a vikingologist in the house?
Tuberculosis keeps coming up. It was deadly and recent and widespread, and it’s implicated in the ‘plausible mechanism’ paper, and in the one about rheumatoid arthritis, and the other day I met an old friend with bladder cancer. Apparently he’s having tuberculosis drugs injected to try to kill it. No one knows why, but it works about 30% of the time!
It would be way interesting if someone had statistics for ancient diseases and statistics for modern unexplained diseases. I’ve no idea what to predict, but I bet it’s not ‘no correlation’.
Have you seen Greg Cochran’s paper on infections?
Yes, I based the entire second post on it, and referenced it. But thanks, that would have been really useful!
I just emailed the address on the paper (paul ewald) to see what they thought of it. But no reply. If anyone knows one of them could you tell them there’s someone wrong on the internet?
Physical trauma doesn’t have to be explained, it’s an explanation. In cases like broken legs it’s a pretty straightforward explanation. In other cases like depression, it get’s more complicated.
An explanation is a chain of causal links, where each one is verified under interventions. If I hit you with a sledgehammer, your leg will break, and we know why, and it’s not that my anger causes ‘stress’, and that breaks your leg by magic stress-property, because I’m stressed too, and yet my leg never breaks.
A vague correlation is not an explanation. It’s a sign that you should look for one. Sure if I attacked you with a sledgehammer, you might get depressed. But why?
Depression in patients with acute traumatic brain injury :
Major depression occurs in about one-quarter of patients after traumatic brain injury. This is the same frequency as in other major disorders such as stroke. Major depression appears to be provoked by one or more factors that include poor premorbid social functioning and previous psychiatric disorder or injury to certain critical brain locations.
Depression among older adults after traumatic brain injury: a national analysis.:
TBI significantly increased the risk of depression among older adults, especially among men and those discharged to a skilled nursing facility. Results from this study will help increase awareness of the risk of depression post-TBI among older adults.
It’s plausible that the trauma kills neurons and thus creates depression. It’s also possible that some fascia tenses up and produces problems. It’s possible that it produces Sensor Motor Amnesia. It’s possible that it creates problematic inflammation.
There are a lot of plausible mechanisms to choose from.
Agreed. Thanks. It was more a sort of philosophical point about the nature of explanation. We might be able to tell which of these counted as an explanation by intervening later on in the proposed causal chain and seeing if the same results obtain.
As far as the philosophy goes, for most successful interventions in health care we don’t really know how they work.
Depression usually comes along with increased inflamation of the gut. Depression medicine that’s intented to target the brain because of chemical imbalance, also hit’s targets in the gut.
Does that mean I’m certain that those drugs fight depression by having positive effect on the gut? No, I’m not certain of that, but it’s an open possibility.
“Explanations” in general aren’t good at predicting outcomes for drugs. That way so many clinical trials fail. The only way that seems to work is to gather empiric evidence for treatments. That way you know whether the treatment works but not why it works.
Trolling or eyerolling? You decide!
X-D