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Infection inflicts a persistent decrease in IQ: study with 180,000 participants

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Re: Infection inflicts a persistent decrease in IQ: study with 180,000 participants

#11

Post by unclebucknasty »

madaxe_again wrote: post #4

Interesting study, but as the authors concede, one can't quite rule out that the causal flow is in the opposite direction to that which they propose - that is, people with lower cognitive ability are more likely to end up with infections, and people with much lower cognitive ability are more likely to end up with severe infections. I mean, consider people with dementia, sat in their own faeces (at the severely dimini…

>this reverse association could not account for the observed temporal correlations or the correlations with the severity of infection. Moreover, the correlation between infections and cognitive ability retained significance even after adjustment for other parameters known to influence general cognitive ability...which are also associated with socio-economic gradients.

Could possibly be both.

Re: Infection inflicts a persistent decrease in IQ: study with 180,000 participants

#12

Post by mocha-rain »

madaxe_again wrote: post #4

Interesting study, but as the authors concede, one can't quite rule out that the causal flow is in the opposite direction to that which they propose - that is, people with lower cognitive ability are more likely to end up with infections, and people with much lower cognitive ability are more likely to end up with severe infections. I mean, consider people with dementia, sat in their own faeces (at the severely dimini…

I'm sympathetic to your point of view; in some cases it seems nearly impossible to rigorously exclude reverse-associations when there are so many complexities.

The authors respond to this objection as follows:

The finding that infections are associated with decreased general cognitive ability after a latency period might be an epiphenomenon and not a biologically-mediated relationship. For instance, a reverse association could have existed so that lower cognitive ability may be a risk factor for acquiring infections. Furthermore, studies have indicated that immune related genes might be implicated in cognition [34], and individuals with genetic liability towards a lower general cognitive ability might also be more genetically vulnerable towards infections. However, although a genetic or reverse association could have partly explained some of the observed associations, this probably does not account for the observed temporal associations or the associations with severity of the infection.

The association between infections and cognitive ability remained significant after adjusting for other factors known to influence a decrease of general cognitive ability, such as gestational age, birth weight [35], and having more older siblings (i.e. being later in a sibship), which often correlate with socio-economic gradients [36]. ..Nevertheless, the findings remained significant also after adjustment for an individual or family history of psychiatric disorders and substance abuse which could be associated with several of these unmeasured risk factors as well as socio-economic factors. Furthermore, the possible effect of maternal smoking during pregnancy should to some degree be captured by the included birth weight and gestational age in the adjustments. Moreover, there may be diseases that are associated with both increased susceptibility to infections and somewhat lower cognition (either the disease itself or its treatment).

Re: Infection inflicts a persistent decrease in IQ: study with 180,000 participants

#13

Post by unclebucknasty »

jacquesm wrote: post #10
melted wrote: post #8

Earlier quoted context omitted.

This could be because you're not getting enough sleep (or aren't sleeping well due to e.g. apnea or something). Set up a simple experiment: go to bed 1-1.5 hours earlier than you usually do for a couple of weeks and see if your "cognitive decline" disappears. As you age you might find you need more sleep.

> As you age you might find you need more sleep. This is very true for me, much to my surprise. I used to get by on 3 to 4 hours every night but that seems to have really caught up with me. If I don't get 8 hours minimum now I'm woozy the rest of the day.

Same here. And "buzzy" when I'm really sleep-deprived. It literally feels like low-level electrical interference running through my head and my thinking and focus are nowhere near as sharp.

It is like some sort of intoxication, which is fitting, because one of the things sleep does for us is clear toxins from our brains.

Re: Infection inflicts a persistent decrease in IQ: study with 180,000 participants

#14

Post by BoardsOfCanada »

The p-value (a function used for testing a statistical hypothesis) corresponding to these results was less than 0.001, indicating that the probability that the findings were due to chance alone (or that the null hypothesis is true) is less than 0.1%.

Actually, I think it means that IF the null hypothesis is true, there is only a 0.1% chance that we would get this much deviation (or more) from it due to chance. Which isn't the same thing. Still, seems like a significant result of course, but let's be correct about these things.

Re: Infection inflicts a persistent decrease in IQ: study with 180,000 participants

#16

Post by unclebucknasty »

melted wrote: post #8
madaxe_again wrote: post #5

Earlier quoted context omitted.

Cognitive decline happens whether you like it or not, I'm afraid to say. I've hit my early 30s and I've started noticing that I'm far more prone to inappropriately replaced words, can't memorise long strings of digits as well as I used to be able to, and so-forth.

This could be because you're not getting enough sleep (or aren't sleeping well due to e.g. apnea or something). Set up a simple experiment: go to bed 1-1.5 hours earlier than you usually do for a couple of weeks and see if your "cognitive decline" disappears. As you age you might find you need more sleep.

Good point on the apnea, which tends to come with age, especially if overweight. There are different forms and degrees that don't involve waking and gasping for air, but that could easily impair quality sleep. One sign is consistently feeling unrefreshed after a full night's sleep.

Also a good point about giving it a couple weeks. Chronic sleep deprivation can't be fixed with a night or two of "catching up".

Re: Infection inflicts a persistent decrease in IQ: study with 180,000 participants

#17

Post by jacquesm »

unclebucknasty wrote: post #13
jacquesm wrote: post #10

Earlier quoted context omitted.

> As you age you might find you need more sleep. This is very true for me, much to my surprise. I used to get by on 3 to 4 hours every night but that seems to have really caught up with me. If I don't get 8 hours minimum now I'm woozy the rest of the day.

Same here. And "buzzy" when I'm really sleep-deprived. It literally feels like low-level electrical interference running through my head and my thinking and focus are nowhere near as sharp. It is like some sort of intoxication, which is fitting, because one of the things sleep does for us is clear toxins from our brains.

> And "buzzy" when I'm really sleep-deprived. It literally feels like low-level electrical interference running through my head and my thinking and focus are nowhere near as sharp.

That's eerie, I have that too. Especially when it is totally quiet in the house. At first I thought it was because I heard the refrigerator, but I switched that off to rule it out. Then I powered down the whole house and the low humming remains. I'll have to try this when I'm totally rested to see if it goes away then, I never made the link to lack of sleep.

Re: Infection inflicts a persistent decrease in IQ: study with 180,000 participants

#19

Post by axonopathy »

BoardsOfCanada wrote: post #14

The p-value (a function used for testing a statistical hypothesis) corresponding to these results was less than 0.001, indicating that the probability that the findings were due to chance alone (or that the null hypothesis is true) is less than 0.1%. Actually, I think it means that IF the null hypothesis is true, there is only a 0.1% chance that we would get this much deviation (or more) from it due to chance. Which…

It looks like the author took this comment to heart.

Re: Infection inflicts a persistent decrease in IQ: study with 180,000 participants

#20

Post by unclebucknasty »

jacquesm wrote: post #17
unclebucknasty wrote: post #13

Earlier quoted context omitted.

Same here. And "buzzy" when I'm really sleep-deprived. It literally feels like low-level electrical interference running through my head and my thinking and focus are nowhere near as sharp. It is like some sort of intoxication, which is fitting, because one of the things sleep does for us is clear toxins from our brains.

> And "buzzy" when I'm really sleep-deprived. It literally feels like low-level electrical interference running through my head and my thinking and focus are nowhere near as sharp. That's eerie, I have that too. Especially when it is totally quiet in the house. At first I thought it was because I heard the refrigerator, but I switched that off to rule it out. Then I powered down the whole house and the low humming re…

Ok, now this is really funny. There's the buzzy feeling, which I considered distinct from the low hum (til now), but I absolutely hear that low-hum too and also assumed it was the refrigerator. It is more pronounced at certain times, but I never linked it to my sleep deprivation. I'll have to pay attention to that.

Another thing is that I seem to be "sensitive" to some electronics. For instance, I cannot hold a cell phone to my head for more than a few minutes and I even have to take breaks when listening to music on headphones. The feeling I get bears some similarity to my sleep-deprived state, so I have wondered about a relationship there, if not just a further reduction of my tolerance of electronics.

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