The title is misleading, at least on the IQ claim. The underlying study was observational and did not claim causation.
Medical journals and their associated media summaries are awash with low-certainty studies that get de-nuanced and overhyped. These studies are relatively easy to do - not to denigrate the work put in by the original study authors (it’s not their fault the press sensationalize their work). But for strong causative claims you ideally would have blinded controlled randomized trials. Sometimes such trials are not feasible, but that doesn’t mean you get to claim causation anyway just because the work to prove it is too hard.
There are cases (enough to not be treated as just some random coincidence; with and without vaccination) where people after Covid had a sever reduction of cognitive abilities that they have problems filling out relatively simple forms. So we can clearly speak of a reduction of IQ.
And while there is a lot of research needed and a lot of open questions and already half a year (or so?) into the pandemic we did know from how we observed COVID affecting the brain that it likely will cause a reduction in cognitive abilities at least in some cases which matches the (very many) observations we had since then.
This also matches what we know from other older studies about other virus infections which have some similarity with covid, e.g. causing Neuroinflammation. So every thing we observe and do know about the underlying mechanics implies that there is very likely a causation. (Through we need more studies for Neuroinflammation.)
So scientist do need to research it more and do need to pin down the exact mechanisms this causes reduction of cognitive abilities in some cases to largely varying degrees and how much of it is a direct and a indirect e.g. psychological effect.
But for everyone else it best to assume that getting COVID might reduce IQ if they are unlucky. Because if you aren't a doctor, scientist or similar but just a random person who got COVID it kind doesn't matter if your IQ gets reduced by COVID directly or indirectly or just correlated due to some other factor you don't know about and in turn can't systematically avoid.
That's why the most important element in science is replication - direct (repeating the same experiment) and indirect (refining the original experiment, or testing for the opposite result, or an alternative - here we could test reflexes instead of IQ).
And here there is already a lot of replication for several years - plus direct observation of bleeding into the brain.
Maybe something like people with lower IQ are less likely to do a job where they can work from home so they are more likely to have been exposed to the virus?
Neuroinflammation is a poorly studied area and one likely cause of brain fog and mecfs/long covid symptoms. Jarred Younger [1] is a researcher studying this and has a youtube channel [2] where he discusses his latest work. If you're interested in this it's worth watching!
Also please ignore anyone that posts 'oh its just X' or 'just do X', whatever X may be. This is a complicated medical mystery that millions of patients have suffered from for decades if you include mecfs and postviral conditions. There is no X, patients have tried every possible X. Anyone who tells you its just X is revealing their lack of understanding of the issue (this happens every time this subject shows up on HN and elsewhere).
My wife has postcovid and this is a profound effect. Yesterday she tried to add up a series of numbers by heart, and she simply couldn’t. For context, she’s pretty mathy and used to mock me for taking out a calculator or a spreadsheet for stuff like that. She also forgets everything, which is another thing she used to be great at. It’s pretty confronting, especially now that the idea that maybe this isn’t temporary is taking shape.
Odd. I also felt that my memory is not as good as it was used to, and I experiences Doorway effect (https://en.wikipedia.org/wiki/Doorway_effect) more frequently in recent years compare to before.
But I'm not really sure it was due to COVID or just simply being old (or due to been forced to live in a confined space for long period of time).
My wife who is more than 2 years sick with Long/Post Covid, lost almost everything because of it, her body and her brain. She had almost perfect memory and spoke 5 languages fluently by the age of 30 while learning Chinese as a 6th. She had a promising career in the medicine field and was also quite a good painter and other crafts (not famous though). We were hiking regularly to very high mountains and doing a lot of activities.
Now she spends most of the day in bed and the rest on the sofa and she can’t barely do anything, only crochet… maybe some cooking. Not even watch movies that have too much action, so she is watching black and white series now to have something to do without getting cognitively burnout. She lost her memory, her capacity to think, she has chronic fatigue and many other weird symptoms like easily getting senses overwhelmed by simple noises or smells.
We went to a lot of doctors, tried a few “remedies” from small scientific studies and internet: metformin, nicotine, lidocaine, multiple supplements and vitamins, some antivirals and many other things. Nobody is able to help her and most of doctors don’t even try to help or know anything about this new and growing condition.
Of course always the “psychosomatic” smart ass appears, but there are enough proofs already to tell them to shut up. Even the NIH director mentioned viral persistence found body tissues in a recent talk [1].
At least the awareness is growing and there are s lot of studies going on. So still some hope, but it won’t come fast.
For me it's gotten better. I got sick in August 2021, the major effects (fatigue and brain fog) were most pronounced between September and February, and I've been steadily improving since. I think I'm somewhere around 80% pre-Covid capacity most days.
I got infected with COVID twice, thankfully only after being vaccinated and didn't experience heavy physical effects but the cognitive issues I had on my first infection triggered a really bad anxiety.
At some point I was playing chess with my girlfriend after 4-5 days from getting symptoms, after 3 moves (so pretty much still in the beginning of the openings) my brain simply could not understand what I was trying to do, like I couldn't connect a previous thought to the next, there was an impassable barrier between these thoughts that I couldn't get through.
It got worse when I realised I had no idea what I was doing and while looking at the board I couldn't remember how the pieces moved, I looked at my bishop on the board and couldn't think where it could go. I started to cry, my whole job is to think things through, connect diverging thoughts, I got extremely scared I was going to lose this basic ability that enables me to do my job...
I lost the senses of smell and taste for about 10 days so definitely had neurological issues from COVID, the feeling of not being able to think properly was the worse of the feelings. The fever was ok, never broke too high and it was short-lived for about a couple of hours, feeling my heart was not comfortable but bearable and I wouldn't get too tired.
I'm so glad it was temporary, and so sorry for your wife having this lingering on her, I do not wish it to anyone.
There is an interesting paper (the main author seems to be from Netherlands, too) about potential mechanism of action that makes Covid infections have long-term repercussions published last year at https://www.frontiersin.org/journals/immunology/articles/10.....
> Based on these data, we hypothesize that the shift to anaerobic respiration causes an acid-base disruption that can affect every organ system and underpins the symptoms of PASC.
(Brain, of course, is also an organ, so brain fog and reduction in mental capabilities could easily fall under this.)
My girlfriend has pretty bad post-covid, the thing that helped her most was getting on Citalopram. There's suspicions that many SSRI's have a anti-inflammatory effect on the brain, which might be the mechanism.
She's currently in oxygen therapy, we're positive about the effects but since it's dominating her life (and energy) at the moment it's hard to say what the effect is.
I have a very math-heavy competitive hobby which I found myself suddenly very bad at (relative to my previous performance) for 6-8 weeks after all my other covid symptoms were gone.
I appear to have recovered within 90 days, but I don’t know if I was left with permanent damage or not. I had no way to objectively test.
I watched my partner have a very bad run in with Epstein-Barr Virus (a decade ago). Wiped her out for months and months. It took years before she was back to 100%.
It might not be clear what all the causes of long-covid, brain fog are but it's definitely possible for viruses to have long lasting and poorly studied impacts.
2015 observational study suggests these results are not unique to Covid: ""Our research shows a correlation between hospitalisation due to infection and impaired cognition corresponding to an IQ score of 1.76 lower than the average. People with five or more hospital contacts with infections had an IQ score of 9.44 lower than the average. The study thus shows a clear dose-response relationship between the number of infections, and the effect on cognitive ability increased with the temporal proximity of the last infection and with the severity of the infection." Source: https://www.sciencedaily.com/releases/2015/05/150521095016.h...
In about 5 minutes I found papers on cognitive impairment for post-covid groups vs healthy controls in multiple non-North American countries, including one from Spain [1] where there was a measurably lower correlating IQ estimation for the PCC group than the HC group.
> A significant proportion of individuals experience persistent fatigue and/or cognitive impairment following resolution of acute COVID-19.
> Ten studies analyzed data from Italy, nine from Spain, eight from the US, seven from China, six from the UK, three from Denmark, France, and Norway, respectively, two from Australia, Austria, Brazil, Canada, Egypt, Germany, Israel, Russia, and the Netherlands, respectively, and one from Belgium, the Czech Republic, England, Faroe Islands, Iran, Japan, Mexico, Pakistan, Singapore, Sweden, Switzerland, and Turkey, respectively...
It's almost impossible to compare IQ tests across countries, because cognition test results are really only valid for people from the cultural context the test was written for.
The cognitive decline can also be attributed to extreme isolation that everyone was subjected to. My super enriched, flow like heavenly water life came to a complete standstill. All future plans and timelines thrown in disarray. Covid has ended but my life trajectory has completely changed
Yes, I mean it's been shown how people with a loss of hearing have an increased risk of dementia and it's natural that this would apply here as well. It's just another form of lost stimuli. But there might also be medical reasons behind this and this serves to show how complex this is to research.
Faust: I just want to follow up on something you said a moment ago about where this virus can be found in tissues. Are you suggesting that long COVID is actually, the mechanism of that, is persistent live virus in humans?
Bertagnolli: We see evidence of persistent live virus in humans in various tissue reservoirs, including surrounding nerves, the brain, the GI [gastrointestinal] tract, to the lung.
Faust: OK. And you're saying this goes beyond the PCR's [polymerase chain reaction test] ability to get it in a regular swab so that we are missing chronic cases of SARS‑CoV‑2?
Bertagnolli: Correct. The virus can persist in tissues for months, perhaps even years.
Faust: OK. I think that's certainly one theory, but I'm not sure that that's settled. Is that fair? I mean, there's one thing between people who are autopsy, they died of viral sepsis, as opposed to people walking around. Is there a distinction there?
Bertagnolli: Our emerging data shows that the virus can persist into tissues in the long term, and I think that's really critical because it does help us think about possible ways to combat it, one being better antivirals. I think there's a lot of focus on developing new antivirals as a possible way of preventing long COVID, and the other might be more aggressive treatment with antiviral therapy upon initial diagnosis.
Faust: If that's the case, then it could be reactivated just like herpes is and shingles. Are we going to start seeing people get COVID not from infection, but from themselves in reactivation?
Bertagnolli: I don't believe I've seen or heard of any instance of that, and I don't think you can ever assume that one virus is going to act like another. Certainly every virus that we know of seems to have a different effect in the body long term.
I've noticed my memory and math skills getting worse as well. Can't say it's covid for sure though as there are other likely explanations too: getting fatter and out of shape, finishing uni and going out of practice, long-term sleep deprivation, etc.
Either way, if not covid, then I think at least the lockdowns did have an impact on my health and ability to stay fit.
I'm dismayed by the number of people who apparently don't subscribe to evidence-based medicine using proper statistical methodology and instead rely on anecdotal evidence whenever Covid comes up. It's very irrational, though some of this behavior can probably be explained by the extreme politicization of the topic in the US.
The symptoms of tingling in the extremities resemble what my wife experienced after her chemo when the treatment damaged her neurons' myelin sheath. This causes 'noisy' neuron signals to be transmitted (tingles, lack of sensation, etc.).
If the same thing happened in the brain, I bet the noisy signals would lead to brain fogginess, forgetfulness, etc. Back then, she was taking omega-3 supplements and received shots of vitamin B12. After a year, it removed almost all the tingling, but some sensations never fully came back.
This is not medical advice (and check with your doctor beforehand), but it feels like taking vitamin B12 and omega-3 supplements should be a pretty low-risk bet to try to improve your situation if you're experiencing the long COVID symptoms described in the article.
I went through a mild COVID-19 infection, and felt the sluggishness in my brain for quite some time. I think I recovered, but it was a jarring experience.
I think I'd attribute my newfound slowness to lockdowns, rather than COVID?
Lack of practicing talking and remembering stuff is bad for talking and remembering stuff, and it definitely happened long before I caught COVID, because I caught COVID super late
The studies cited do not prove any causative association. They lack controls and other design elements that would account for misattribution and the impact of COVID-related psychosocial factors on observed symptoms.
In general, there is an extreme lack of rigor seen in claims about long COVID. The best evidence available suggests most cases of "long COVID" are misattribution:
> There are studies that have been done comparing people who had COVID-19, versus people who didn't, and then gave them cognitive testing to measure their ability to cognitively process information and test their IQ. And there's very clear differences in the IQ of people who had been infected with COVID-19 versus people who did not. Even mild COVID can give people about a three-point loss of IQ.
That sounds like an observational study. It's hard to get from that correlation to the causation in the headline. The article does not mention this problem at all as far as I can tell.
I definitely feel 'less sharp' at times, however in my case I may have other factors going on. I did have Omicron and possibly something very weird about the time Covid started to show up in the USA
[+] [-] jl6|1 year ago|reply
Medical journals and their associated media summaries are awash with low-certainty studies that get de-nuanced and overhyped. These studies are relatively easy to do - not to denigrate the work put in by the original study authors (it’s not their fault the press sensationalize their work). But for strong causative claims you ideally would have blinded controlled randomized trials. Sometimes such trials are not feasible, but that doesn’t mean you get to claim causation anyway just because the work to prove it is too hard.
[+] [-] dathinab|1 year ago|reply
There are cases (enough to not be treated as just some random coincidence; with and without vaccination) where people after Covid had a sever reduction of cognitive abilities that they have problems filling out relatively simple forms. So we can clearly speak of a reduction of IQ.
And while there is a lot of research needed and a lot of open questions and already half a year (or so?) into the pandemic we did know from how we observed COVID affecting the brain that it likely will cause a reduction in cognitive abilities at least in some cases which matches the (very many) observations we had since then.
This also matches what we know from other older studies about other virus infections which have some similarity with covid, e.g. causing Neuroinflammation. So every thing we observe and do know about the underlying mechanics implies that there is very likely a causation. (Through we need more studies for Neuroinflammation.)
So scientist do need to research it more and do need to pin down the exact mechanisms this causes reduction of cognitive abilities in some cases to largely varying degrees and how much of it is a direct and a indirect e.g. psychological effect.
But for everyone else it best to assume that getting COVID might reduce IQ if they are unlucky. Because if you aren't a doctor, scientist or similar but just a random person who got COVID it kind doesn't matter if your IQ gets reduced by COVID directly or indirectly or just correlated due to some other factor you don't know about and in turn can't systematically avoid.
[+] [-] aredox|1 year ago|reply
And here there is already a lot of replication for several years - plus direct observation of bleeding into the brain.
https://www.tcd.ie/news_events/articles/2024/trinity-team-di...
[+] [-] rjmunro|1 year ago|reply
Maybe something like people with lower IQ are less likely to do a job where they can work from home so they are more likely to have been exposed to the virus?
[+] [-] camgunz|1 year ago|reply
[+] [-] p0w3n3d|1 year ago|reply
[+] [-] gn4d|1 year ago|reply
[+] [-] throwaway48476|1 year ago|reply
[deleted]
[+] [-] npunt|1 year ago|reply
Also please ignore anyone that posts 'oh its just X' or 'just do X', whatever X may be. This is a complicated medical mystery that millions of patients have suffered from for decades if you include mecfs and postviral conditions. There is no X, patients have tried every possible X. Anyone who tells you its just X is revealing their lack of understanding of the issue (this happens every time this subject shows up on HN and elsewhere).
[1] https://me-pedia.org/wiki/Jarred_Younger
[2] https://www.youtube.com/channel/UCoVoOvIX90IMEZCbBf_ycEA
[+] [-] ImHereToVote|1 year ago|reply
[+] [-] skrebbel|1 year ago|reply
[+] [-] nirui|1 year ago|reply
But I'm not really sure it was due to COVID or just simply being old (or due to been forced to live in a confined space for long period of time).
[+] [-] user568439|1 year ago|reply
Now she spends most of the day in bed and the rest on the sofa and she can’t barely do anything, only crochet… maybe some cooking. Not even watch movies that have too much action, so she is watching black and white series now to have something to do without getting cognitively burnout. She lost her memory, her capacity to think, she has chronic fatigue and many other weird symptoms like easily getting senses overwhelmed by simple noises or smells.
We went to a lot of doctors, tried a few “remedies” from small scientific studies and internet: metformin, nicotine, lidocaine, multiple supplements and vitamins, some antivirals and many other things. Nobody is able to help her and most of doctors don’t even try to help or know anything about this new and growing condition.
Of course always the “psychosomatic” smart ass appears, but there are enough proofs already to tell them to shut up. Even the NIH director mentioned viral persistence found body tissues in a recent talk [1].
At least the awareness is growing and there are s lot of studies going on. So still some hope, but it won’t come fast.
[1] https://x.com/californiacodes/status/1780099073468764415
[+] [-] underdeserver|1 year ago|reply
For me it's gotten better. I got sick in August 2021, the major effects (fatigue and brain fog) were most pronounced between September and February, and I've been steadily improving since. I think I'm somewhere around 80% pre-Covid capacity most days.
[+] [-] piva00|1 year ago|reply
At some point I was playing chess with my girlfriend after 4-5 days from getting symptoms, after 3 moves (so pretty much still in the beginning of the openings) my brain simply could not understand what I was trying to do, like I couldn't connect a previous thought to the next, there was an impassable barrier between these thoughts that I couldn't get through.
It got worse when I realised I had no idea what I was doing and while looking at the board I couldn't remember how the pieces moved, I looked at my bishop on the board and couldn't think where it could go. I started to cry, my whole job is to think things through, connect diverging thoughts, I got extremely scared I was going to lose this basic ability that enables me to do my job...
I lost the senses of smell and taste for about 10 days so definitely had neurological issues from COVID, the feeling of not being able to think properly was the worse of the feelings. The fever was ok, never broke too high and it was short-lived for about a couple of hours, feeling my heart was not comfortable but bearable and I wouldn't get too tired.
I'm so glad it was temporary, and so sorry for your wife having this lingering on her, I do not wish it to anyone.
[+] [-] strogonoff|1 year ago|reply
> Based on these data, we hypothesize that the shift to anaerobic respiration causes an acid-base disruption that can affect every organ system and underpins the symptoms of PASC.
(Brain, of course, is also an organ, so brain fog and reduction in mental capabilities could easily fall under this.)
[+] [-] TheFreim|1 year ago|reply
[+] [-] changelink|1 year ago|reply
She's currently in oxygen therapy, we're positive about the effects but since it's dominating her life (and energy) at the moment it's hard to say what the effect is.
[+] [-] sneak|1 year ago|reply
I appear to have recovered within 90 days, but I don’t know if I was left with permanent damage or not. I had no way to objectively test.
[+] [-] eleveriven|1 year ago|reply
[+] [-] vertis|1 year ago|reply
It might not be clear what all the causes of long-covid, brain fog are but it's definitely possible for viruses to have long lasting and poorly studied impacts.
[+] [-] jeffhuys|1 year ago|reply
[+] [-] madballster|1 year ago|reply
[+] [-] michael9423|1 year ago|reply
"People with five or more hospital contacts with infections had an IQ score of 9.44 lower than the average."
https://www.sciencedaily.com/releases/2015/05/150521095016.h...
[+] [-] bratbag|1 year ago|reply
In my case it was just a vitimin D deficiency caused by working from home.
I don't doubt some people have suffered neurological damage, but I wouldn't be surprised if many are suffering the same as I was.
[+] [-] prmoustache|1 year ago|reply
[+] [-] henrikschroder|1 year ago|reply
Five bucks says you won't find that.
[+] [-] kromem|1 year ago|reply
1 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9631485/
Do you have a more specific hypothesis of what wouldn't be found elsewhere? Because it looks like you'd be out of $5 from any takers currently.
[+] [-] helsinkiandrew|1 year ago|reply
https://pubmed.ncbi.nlm.nih.gov/34973396/
> A significant proportion of individuals experience persistent fatigue and/or cognitive impairment following resolution of acute COVID-19.
> Ten studies analyzed data from Italy, nine from Spain, eight from the US, seven from China, six from the UK, three from Denmark, France, and Norway, respectively, two from Australia, Austria, Brazil, Canada, Egypt, Germany, Israel, Russia, and the Netherlands, respectively, and one from Belgium, the Czech Republic, England, Faroe Islands, Iran, Japan, Mexico, Pakistan, Singapore, Sweden, Switzerland, and Turkey, respectively...
[+] [-] danielheath|1 year ago|reply
[+] [-] rchtwlm|1 year ago|reply
[+] [-] skrebbel|1 year ago|reply
[+] [-] solumunus|1 year ago|reply
[+] [-] negamax|1 year ago|reply
[+] [-] jug|1 year ago|reply
[+] [-] zjp|1 year ago|reply
[+] [-] throwing_away|1 year ago|reply
https://www.medpagetoday.com/opinion/faustfiles/109672 -- an interview from 2 days ago where the NIH leader says covid is persistent for months or years in people and the MD interviewer did a double take.
Not sure why there's a shift happening, maybe some new publication? This has been shaping up for years now.
[+] [-] greyface-|1 year ago|reply
Faust: I just want to follow up on something you said a moment ago about where this virus can be found in tissues. Are you suggesting that long COVID is actually, the mechanism of that, is persistent live virus in humans?
Bertagnolli: We see evidence of persistent live virus in humans in various tissue reservoirs, including surrounding nerves, the brain, the GI [gastrointestinal] tract, to the lung.
Faust: OK. And you're saying this goes beyond the PCR's [polymerase chain reaction test] ability to get it in a regular swab so that we are missing chronic cases of SARS‑CoV‑2?
Bertagnolli: Correct. The virus can persist in tissues for months, perhaps even years.
Faust: OK. I think that's certainly one theory, but I'm not sure that that's settled. Is that fair? I mean, there's one thing between people who are autopsy, they died of viral sepsis, as opposed to people walking around. Is there a distinction there?
Bertagnolli: Our emerging data shows that the virus can persist into tissues in the long term, and I think that's really critical because it does help us think about possible ways to combat it, one being better antivirals. I think there's a lot of focus on developing new antivirals as a possible way of preventing long COVID, and the other might be more aggressive treatment with antiviral therapy upon initial diagnosis.
Faust: If that's the case, then it could be reactivated just like herpes is and shingles. Are we going to start seeing people get COVID not from infection, but from themselves in reactivation?
Bertagnolli: I don't believe I've seen or heard of any instance of that, and I don't think you can ever assume that one virus is going to act like another. Certainly every virus that we know of seems to have a different effect in the body long term.
[+] [-] Satam|1 year ago|reply
Either way, if not covid, then I think at least the lockdowns did have an impact on my health and ability to stay fit.
[+] [-] jonathanstrange|1 year ago|reply
[+] [-] maaaaattttt|1 year ago|reply
This is not medical advice (and check with your doctor beforehand), but it feels like taking vitamin B12 and omega-3 supplements should be a pretty low-risk bet to try to improve your situation if you're experiencing the long COVID symptoms described in the article.
[+] [-] bayindirh|1 year ago|reply
[+] [-] 8note|1 year ago|reply
Lack of practicing talking and remembering stuff is bad for talking and remembering stuff, and it definitely happened long before I caught COVID, because I caught COVID super late
[+] [-] robocat|1 year ago|reply
Why do you assume that you weren't asymptomatic?
[+] [-] ETH_start|1 year ago|reply
In general, there is an extreme lack of rigor seen in claims about long COVID. The best evidence available suggests most cases of "long COVID" are misattribution:
https://jamanetwork.com/journals/jamainternalmedicine/fullar...
[+] [-] eru|1 year ago|reply
That sounds like an observational study. It's hard to get from that correlation to the causation in the headline. The article does not mention this problem at all as far as I can tell.
[+] [-] feverzsj|1 year ago|reply
[+] [-] unknown|1 year ago|reply
[deleted]
[+] [-] shrubble|1 year ago|reply