15 ms·

Cognitive deficits in people who have recovered from Covid-19

250 points by luu 6y ago

kasperni 6y ago
From the conclusion: "The scale of the observed deficits was not insubstantial; the 0.57 SD global composite score reduction for the hospitalised with ventilator sub-group was equivalent to the average 10-year decline in global performance between the ages of 20 to 70 within this dataset. It was larger than the mean deficit of 512 people who indicated they had previously suffered a stroke (-0.40SDs) and the 1016 who reported learning disabilities (-0.49SDs). For comparison, in a classic intelligence test, 0.57 SDs equates to an 8.5-point difference in IQ."
- redis_mlc 6y ago
  > the hospitalised with ventilator sub-group So this affects almost nobody then, and is probably caused by the sedatives, immobilization and ventilator organ damage, aside from corona.
  - fogihujy 6y ago
    Well, the fact that someone was uable to breathe on their own also suggests that the virus may have caused a lack of oxygen to the brain. In such circumstances brain damage is quite likely, and then the disease would indeed be the cause. Fortunately, the group of people that end up on ventilators is not really that large, and I can imagine minor brain damage would still be preferable to death in many of those cases. As a sibling commented, theeffects that won't start to manifest until a year or two has passed are more worrying. There's simply so much we don't know about this virus yet.
    - neuronic 6y ago
      People are unable to worry about or comprehend the effects that happen right NOW. I am a staunch believer in post-viral syndrome as I experienced it first hand following an Epstein-Barr infection (mono) but aside from a handful of researchers nobody cares at all. For most physicians, it isn't even within the realm of possibilities when you come to them with random maladies. Boom, now you have anxiety because that's what they tell you when they don't know shit. There are so many bodily issues that arose after my Epstein-Barr infection, it's not funny at all. I can absolutely lead a normal life and am active and athletic. But things like autoimmune issues, persistent 15-year brain fog (I'd rather call it frosted glass layer) which randomly clears once a month to remind me how nice it is to be able to think straight, or full-body-numbing attacks in the middle of a gas station. The first 5 years after the disease I regularly felt like passing out. Later I just got dizzy and learned to control it using water and temperature changes (cold water in back of your neck!). I still took on the anxiety story and did something against it. It helped me in many ways but not with post-viral syndrome. It's real and it sucks but it's not being taken seriously at all. I am afraid, some COVID survivors are in for a new life which is different in just the right (but minor) ways to drive you insane. Body just doesn't feel the same as before.
      - rtp 6y ago
        It's amazing how people think a virus that lives latently in B cells and epithelial cells, and is strongly associated with various forms of cancer among a big helping of autoimmune disorders, is incapable of causing post-viral syndromes. No, it must be anxiety, of course! EDIT: Just because a disease makes you frustrated because you can't really do anything about it except empathize and listen, doesn't mean you can just slap the anxiety band-aid on it and call it a day.
        neuronic 6y ago
        Correct, I don't expect doctors to cure me. I expect them to acknowledge that EBV could play a part here. But nope, just anxiety.
      - throwaway1092 6y ago
        > But things like autoimmune issues, persistent 15-year brain fog (I'd rather call it frosted glass layer) which randomly clears once a month to remind me how nice it is to be able to think straight I've been experiencing something similar for the past 5 years: brain fog (frosted glass is a much better way of putting it.) and some short term memory issues. The doctors put me through a battery of tests to find...that they could find no reason for my ailment. Curious to know what if anything has helped you the most. The 'randomly clearing' brain fog for a day happens to me maybe once every 3 months and it's both a blessing and a curse.
        jokab 6y ago
        Sorry to hear this. I cured mine with a CPAP machine. I had to be tested with apnea twice bc the first one came out ok but i wasnt convinced. In any case, i hope you feel better
        throwaway1092 6y ago
        Thanks - already had/have a CPAP machine, so unfortunately that's not it.
      - 6y ago
  - ghufran_syed 6y ago
    Not sure why you’re getting downvoted - here’s a page about post-intensive care syndrome, on the website of the society for critical care medicine, that’s concordant with what you said: https://www.sccm.org/MyICUCare/THRIVE/Post-intensive-Care-Syndrome https://www.sccm.org/MyICUCare/THRIVE/Post-intensive-Care-Sy...
    - noja 6y ago
      > Not sure why you’re getting downvoted I think he overlooked that the people were hospitalized and on ventilators because they had covid.
      - xd 6y ago
        But it's still an effect of the treatment. If you perform a study on people whom have been ill you're going to get results that show all the symptoms of illness.. the study could have been done with any illness and likely show cognitive decline.
        shultays 6y ago
        symptoms of illness is the illness itself. Ignoring these symptoms of covid or results of the treatment is saying something like "bullets don't kill people, it ruptures blood vessels and you die due to loss of blood"
        srtjstjsj 6y ago
        You misunderstand the ambiguous wording. If you study only includes people with an illness, the illness itself is a confounder. The point is that if you have a non-ICU covid case, this research is unlikely to apply.
        jrumbut 6y ago
        It feels like we didn't read the same article, they break down numbers for people on ventilators but also hospitalized, non-ventilator patients all the way down to those who received no particular care. The findings were concerning to anyone who had it, they also mention cases where the cognitive deficit was the first reported symptom.
  - xd 6y ago
    Also, I had a brief look over the paper but couldn't find anything to control for isolation since lockdown .. surely this would of had an effect on peoples cognition. On a side note, maybe it's just me but I keep seeing comments that don't follow a "politically" accepted view point, being down vote like yours.
    - w_t_payne 6y ago
      Maybe it's because this whole situation has been ridiculously politicized, to the point where it's difficult to have a rational fact-based discussion.
      - hejja 6y ago
        ...about anything. not just covid.
        EForEndeavour 6y ago
        That's exactly what someone with your political beliefs would say!!
    - deleted 6y ago
      [deleted]
    - jmull 6y ago
      I don't know why people downvote things, but in this case I would hope it's because the previous comment was pretty superficial. Whether the covid causes cognitive decline through causing the use of a ventilator, sedatives, and immobilization or through some other mechanism still means it causes cognitive decline. So there's a basic logic flaw. Also, quite a large number of people have been put on ventilators due to covid-19, not "almost nobody". That's just an incorrect assertion. You'd like to attribute the downvoting to politics, but given the quality issues, I think that's a hard claim to support.
    - api 6y ago
      If isolation with a net connection for a few months dropped multiple IQ points, then all the shut-ins who do nothing but hang around on the Internet all day would be losing multiple tens of IQ points a year and would be functionally disabled by now.
  - regularfry 6y ago
    The error bars overlap with the "hospitalised without ventilation" group. There's probably something else going on, and the authors do call out the known cognitive effects of hypoxia.
  - nradov 6y ago
    There is some evidence that anesthetics can cause cognitive impairment. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6443620/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6443620/
    - kube-system 6y ago
      I was under the impression, at least as it pertained to the elderly, that GA is commonly known to be a significant risk.
      - nradov 6y ago
        Any type of long hospital stay frequently causes delirium among the elderly. GA makes it worse. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3065676/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3065676/
  - simonh 6y ago
    Most of the impact seems to occur even without serious symptoms: >bio-positive cases who reported being ill with no breathing difficulties showed a 0.32SD magnitude cognitive deficit. My wife's hospital was full to the corridors with 'almost nobody's.
  - paradox242 6y ago
    As other have already commented, they have already considered your theory in their analysis: "Consequently, the observation of post-infection deficits in the subgroup who were put on a ventilator was not surprising. Conversely, the deficits in cases who were not put on a ventilator, particularly those who remained at home, was unexpected." This effect on those hospitalized is not the primary thrust of their paper. Instead it was the observed effects on those who were not hospitalized or had mild to no respiratory symptoms. They raise many possibilities about why this may be the case and only assert that this effect at least proceeds into the recovery phase. I did not read any claims about this being permanent, broadly speaking.
  - biolurker1 6y ago
    As many previous comments said, the article includes mild disease
- st1x7 6y ago
  Reduction equivalent to the cognitive decline of aging 10 years and larger than the cognitive decline of suffering a stroke? Sounds pretty substantial to me.
  - minitech 6y ago
    “not insubstantial” :)
    - dempseye 6y ago
      This is a very English way of expressing oneself.
      - taneq 6y ago
        Well it's not unEnglish.
        metalliqaz 6y ago
        "inflammable means flammable?"
        solarkraft 6y ago
        "all but"
      - deleted 6y ago
        [deleted]
      - julianlam 6y ago
        I also used to find this disturbing, but the way I have explained this to myself is -- Insignificant < 25% Not insignificant 25-50% Not significant 50-75% Significant > 75% Of course for each individual situation the numbers vary, and I use them simply to demonstrate that it's a matter of degrees, and not as binary as you may expect a typical "not" to be. It is the only double negative I have come to find useful.
- sokoloff 6y ago
  It’s equally as surprising to me the suggestion that the average decline in IQ from a stroke would be only 6 points or so.
  - srtjstjsj 6y ago
    It's an average. Strokes can be very small and localized.
  - treeman79 6y ago
    Varies a lot. I get a lot of minor strokes if I skip blood thinners for a week or so. At peak I’m a highly effective programmer. If I’ve had one recently, a “for loop” is a challenging concept. After a few days to weeks I’ll be back to near normal. Some symptoms last longer. Highly active Factor 5 Leiden, so I clot like crazy.
    - hderms 6y ago
      That sounds incredibly difficult. You must be a very strong and intelligent person.
      - treeman79 6y ago
        Thank you, yes beyond challenging. Mostly at this point because I work technical jobs and have no idea how to step down to lower role where periodic reduced intelligence is less of an issue.
  - gen220 6y ago
    The impact of a stroke varies a lot with the kind of stroke, and the proximity of quality treatment. An awful stroke speedily treated by top doctors has the chance of imparting basically no change to cognitive function. Of the same token, not-the-worst strokes with mediocre care can ruin one's capacity to work. It's a really complicated medical event, with high variance in outcome. Strokes suck.
- mrfusion 6y ago
  I’d be curious to see this compared to people hospitalized on ventilators for other diseases. You’re not in good shape at that point and I’d expect all kinds of problems.
  - usrusr 6y ago
    Does it matter though? The answer certainly depends on the context of the question: do we just want to assess the risks more precisely than the dead/alive boolean? No, it doesn't matter. Do we want to increase humanity's knowledge about how the virus affects our bodies? Yes, absolutely, if it's worse than standard damage of respirator episodes we'll want to know the "mechanisms" that we causing that extra damage.
    - mrfusion 6y ago
      If we’re being asked to give up our way of life, keep children out of school, damage mental health, give up essential freedoms. Then yes, I’d like to see it compared to existing diseases we’ve been living normally alongside for centuries!
  - ineedasername 6y ago
    It's not (just) a matter of whether or not Covid is worse than other serious illnesses. It's that whatever existed already, Covid adds on top of that. So if there were X people that experienced significant health problems before, now there are X + Covid.
- cltby 6y ago
  I'm certainly not accusing you of this personally, but it's curious how selectively IQ is accepted/denied on this site. It's real enough for the purposes of covid policy, lead abatement, or whatever other fashionable environmental intervention. In just about every other case, flat out denialism.
  - salicideblock 6y ago
    The general concern with IQ when used for policymaking, or with standardized "intelligence" tests in general, is that they can fail to account for environmental or cultural factors across individuals or populations. In both cases of covid and lead effects, the effect can be measured on the same population, and/or controlled for proxies of those factors (see "when controlling for age, gender, education level, income, racial-ethnic group and pre-existing medical disorders" in the article. So the general concern with the metric can be excluded.
    - cltby 6y ago
      Psychologists are just as adept at "controlling for age, gender, education level, income, racial-ethnic group." The validity of IQ was first established using within-group comparisons.
  - bitdizzy 6y ago
    IQ is somewhat effective as a diagnostic tool for significant impairment and not much else. Your examples of where it is not contentious are exactly cases where you must measure impairments. Do you want to list some example contexts where you witness "flat out denialism"? In any case there is an important point: The variance of measured IQ for the same individual over time is very high. It's hard to extract a signal for that unless there's a severe effect being measured.
    - cltby 6y ago
      > IQ is somewhat effective as a diagnostic tool for significant impairment and not much else This places exactly zero constraints on the utility of IQ tests. Instead of asking why group A scores higher than group B, I can simply ask why group B is impaired relative to group A. Apparently that should be enough to convince you of the validity of the comparison. > The variance of measured IQ for the same individual over time is very high. The test-retest correlations of IQ batteries are typically in the 0.8-0.9 range. For example, the Wechsler test [1]. This makes IQ probably the single most reliable measure in the social sciences. Perhaps you're referring to the Wilson effect, but that's not at issue here. [1] https://images.pearsonclinical.com/images/pdf/wisciv/WISCIVTechReport2.pdf https://images.pearsonclinical.com/images/pdf/wisciv/WISCIVT...
isoprophlex 6y ago
By no means do I want to detract from the severity of covid infections, but a very important question to answer would be "what's the effect of psychotrauma resulting from illness and hospitalization on cognitive function" I feel that my own cognitive functions have declined as well during the pandemic, due to stress and uncertainty alone. I haven't been infected, mind you.
- redis_mlc 6y ago
  > "what's the effect of psychotrauma resulting from illness and hospitalization on cognitive function" Ventilators are extremely physically traumatic - those patients are considered to be the sickest in any hospital.
  - isoprophlex 6y ago
    It must be hell to have a bunch of suited figures tell you "we're putting you to sleep, hope to see you on the other side"... and then wake up intubated.
    - noneeeed 6y ago
      I believe ITU patients often suffer from psychosis while in treatment and PTSD afterwards. Intensive medical intervention really can be incredibly traumatic for many, over and above the trauma of the illness or injury that put you in ITU.
      - treeman79 6y ago
        For me the treatments went bad, it was being ignored and dismissed at every stage. I had a full on embolism in my lung. Multiple doctors and ER missed it. Kept insisting it was anxiety. Only when skin turned completely white did they reluctantly run an x-ray. Oops. Then I had a reaction to blood thinners. Nurses called me a liar, that no one has a bad reaction. Oh turns out it’s fairly common. Had to let it get to a stroke before they would Change medication. Repeat at every stage.
    - 6y ago
Hnrobert42 6y ago
Make sure you note this has yet to be peer reviewed.
- aronpye 6y ago
  Here here
  - ceilingcorner 6y ago
    * Hear hear I had to look that one up. https://www.grammarly.com/blog/here-here-vs-hear-hear/ https://www.grammarly.com/blog/here-here-vs-hear-hear/
    - diu7sieQuee9jai 6y ago
      They probably meant "here here I'm a peer, I'll review for food." ;)
- api 6y ago
  Why is this so far down? Of course this is HN where everyone is an expert on everything. Maybe everyone is an epidemiologist today.
pedro-guimaraes 6y ago
Much is still to be discovered about the virus, science only knows the effects after less than 1 year. The question is, what could long-term effects of this virus? (let's in 10-20 years)
- hejja 6y ago
  true, yet the same can be said of: - any new pharmaceutical - diets (keto, carnivore, etc) - 5g etc point being: modifying behavior due to decade time-horizon unknowns is not really pragmatic.
  - murgindrag 6y ago
    It kind of is. If you see a country next to yours building up a massive army, and starting propaganda about your government being evil, that's a good reason to prepare. If we learned of alien life in the galaxy, we might want to prepare too. And with diets and diseases, if something has a short-horizon effect, that's good evidence it might have a long time-horizon effect too. The seriousness with which I respond to COVID19 is mostly due to short time-horizon effects giving strong implications of possible long time-horizon effects. I'm less concerned about the 3% CFR as I am about the larger portion of individuals who might have long-term disability, lower economic output, etc. If that passes, we'll be feeling that for many decades.
  - akuchling 6y ago
    It does mean not being very careless about getting infected, and weighs against the idea of going for herd immunity without a vaccine. Here's a Twitter thread listing post-infection syndromes from other vital infections: https://mobile.twitter.com/aetiology/status/1318676570467409922 https://mobile.twitter.com/aetiology/status/1318676570467409...
- giantDinosaur 6y ago
  This statement is the 'needs more research' of pandemics, and should be banned from public discourse...!
- nradov 6y ago
andix 6y ago
Does this study take in account, that people who are hospitalized are probably less healthy than a control group, and maybe already have more cognitive deficits then a control group before getting hospitalized?
- regularfry 6y ago
  The PDF is available as a preview.
- thespoonbends 6y ago
  It does not. It mentions "One might posit that people with lower cognitive ability have higher risk of catching the virus. We consider such a relationship plausible; however, it would not explain why the observed deficits varied in scale with respiratory symptom severity.". That is, it attributes that potential causal link as raising incidence of infection (e.g. they may choose to gather in crowds indoors), not as raising the impact of infection. Either way, as a cross-sectional study, it doesn't establish causation, but may be a smoking gun.
cedex12 6y ago
On the subject of side/long term effects of covid: I've heard, second-hand from doctors/physicians, that the long term effects of covid are not necessarily that bad compared to e.g. the flu. The argument being that: 1. covid has been one of the most studied viruses of this kind, so that you have good chances of stumbling upon lots of size effects, simply due to the sheer size of scrutiny. 2. a bad flu also can yield nasty side effects, but we don't talk about that that much. I don't know what to make of that, and since it's second-hand information, I don't even know how true it is… can anyone shed some light on these arguments?
- jansan 6y ago
  The flu can be nasty. I had a severe case a few years back, and IMO I never fully recovered from it. I consider myself healthy, but I feel that this flu was like getting five years older within two week.
  - snazz 6y ago
    (H1N1)pdm09 was the worst illness I've had, both in duration and severity. Interestingly, that flu virus mostly affected younger people. I'd be interested in reading a thorough comparison of H1N1 and SARS-CoV-2.
- deleted 6y ago
  [deleted]
Liquix 6y ago
Has the mechanism by which the virus affects smell been identified? Could this be related at all? Mysterious neurological symptoms (some of which persist after recovery) are more concerning than the current mortality rate IMO. Great to see studies like this being done.
- maxlamb 6y ago
  Yes. https://hms.harvard.edu/news/how-covid-19-causes-loss-smell https://hms.harvard.edu/news/how-covid-19-causes-loss-smell
  - srtjstjsj 6y ago
    More precisely, yes then no. Yes the smell effect is studied, no it's not neurological.
kmm 6y ago
13050 people report having had covid, but only 361 had had a positive test? How reliable is it that those without a test actually had covid? What if people with lower cognitive ability are more likely to falsely report having had it. > Only a small proportion (0.76%) of participants reported having residual symptoms, Unless I'm misunderstanding something, it seems wrong to calculate that rate over all participants. Someone reporting not being ill can by definition not have residual symptoms. Correcting for that, the proportion with residual symptoms is 4.7%
- NumberCruncher 6y ago
  > What if people with lower cognitive ability are more likely to falsely report having had it. And that's why we generally shouldn't base studies on self reported data. If you had the opportunity to compare self reported data to empiric data (measured, tracked, etc.) you wouldn't believe self reported data any more, because it's heavily biased. BTW I am pretty sure we could observe significant cognitive deficits by people abducted by aliens as well...
- Out_of_Characte 6y ago
  "Someone reporting not being ill can by definition not have residual syptoms" Ofcourse they can. This is trivially proven by the fact that alot of people lose their sense of smell after a covid infection. Even mostly asymptomatic people have reported this. "It’s not uncommon for upper respiratory infections such as the common cold or flu to affect our senses of smell and taste. In fact, it’s estimated that a temporary loss of smell happens in over 60 percent of colds and sinus infections." This is why self-reporting is a different ball-game, I (used) to not consider myself 'sick' and symptomatic if I had a minor flu or cold. One can most definitely report 'not being ill' from coronavirus and suffer residual symptoms. https://www.healthline.com/health/coronavirus-loss-of-taste-loss-of-smell#an-early-symptom https://www.healthline.com/health/coronavirus-loss-of-taste-...
  - kmm 6y ago
    If you look at the study you'll find that of the 71235 people who reported not being ill, exactly 0 have residual symptoms. I'm assuming selecting the option would have been in impossible in the form. If you have (or think you have) a residual symptom of covid, by definition you must have had it, or think you had it. "Ill" here simply means having contracted the virus.
rodolphoarruda 6y ago
I would be nice if the HN link could reflect the wording found in the article's Abstract: "Case studies have revealed neurological problems in severely affected COVID-19 patients." By adding "severely affected" to the context the authors set an important scope of analysis to their study.
- doktrin 6y ago
  That's not their scope of analysis, that's just the introductory sentence. It's meant to reflect on the existing body of knowledge prior to their study. To paraphrase, it's essentially saying "this is what we know already, and here is what we're adding to the body of knowledge with this study" As always, it's best to read the source material directly but these are relevant excerpts from the abstract : "Case studies have revealed neurological problems in severely affected COVID-19 patients. However, there is little information regarding the nature and broader prevalence of cognitive problems post-infection or across the full spread of severity... ...People who had recovered, including those no longer reporting symptoms, exhibited significant cognitive deficits when controlling for age, gender, education level, income, racial-ethnic group and pre-existing medical disorders. They were of substantial effect size for people who had been hospitalised, but also for mild but biologically confirmed cases who reported no breathing difficulty." The last part directly contradicts the idea that this study is limited in scope to severe cases.
HoverSausage 6y ago
The study says "They (significant cognitive deficits) were of substantial effect size for people who had been hospitalised, but also for mild but biologically confirmed cases who reported no breathing difficulty." So according to that study, it doesn't appear to be from ventilators if the effect is also seen in mild cases. Or am I reading it wrong?
- cpncrunch 6y ago
  The effect for non-hospitalised was only around 0.1 SD, so quite small.
baxtr 6y ago
What I’m wondering: people talk about long term effects and we have 9-10 months of data. I remember I had a cold couple of years back and couldn’t taste nor smell for 3 months or so. What about long term effects for people who have gone through other diseases like the flu for example?
- flattone 6y ago
  Also what about things like haircuts. And other stuff. Burnt toast. Hang nails. I apologize. I never get more than 4 hours of Sleep. And this seems like a friendly jab over wanting to compare the flu to a different virus. Pure humor from an also honest place.
- djsumdog 6y ago
  It's just way to early for us to be talking about "longer term" effects. In my 20s, I remember it took nearly a month to recovery from pneumonia. I was lucky. Another friend of mine got pneumonia from a viral infection and was out three months and had to take an Incomplete on all his classes for the semester. All infections have the potential for permanent effects, but they're often not common. An interesting example is Lymes Disease. We still don't understand long term Lymes, but for some reason, the immune system continues to react long after the infection is gone.
woeirua 6y ago
It seems that if you develop severe respiratory issues with Covid that you’re going to be hypoxic for a long time, and potentially with very low O2 saturations. Under those conditions, I frankly would be surprised if we didn’t see signs of cognitive impairment.
ceilingcorner 6y ago
This is perhaps impossible to test (which shows the fundamental weakness of social science) but I think it's nonetheless relevant: studies like this don't factor in overall societal attitude. I can't be the only one that has felt tired, depressed, and just plain bewildered over the past six months. The pessimistic doomsday mentality affects everyone, even if you don't actually get the virus. If I took an IQ test today, I bet I would fare worse than pre-COVID (and I haven't gotten it.)
- spuz 6y ago
  They are comparing test results of people who reported having a positive covid-19 test vs those that reported no positive test or symptoms. The timing of the study should not be a factor.
  - ceilingcorner 6y ago
    Good point. Thanks for the info.
fasteo 6y ago
A quick Google search reveals that cognitive deficit seems to be a common consequence in any critically ill patient, not just Covid-19 This study[1] of just one example: Cognitive dysfunction is an important long-term complication of critical illness associated with reduced quality of life, increase in healthcare costs, and institutionalization And the numbers are certainly high: Cognitive impairment was identified in 206 (49.9%) patients, 120 (29.1%) patients had mild or moderate cognitive impairment, and 86 (20%) patients had severe cognitive dysfunction. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5316231/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5316231/
- simonh 6y ago
  Sure as you say critical illness with long term medical effects is known to have this impact. The difference is that, as the abstract points out, substantial cognitive impairment in Covid patients was found even in people who displayed mild symptoms and were never critically ill.
  - fasteo 6y ago
    Fair point. I missed that part. Thanks. Now we should also research if viral infections in general have an association to cognitive deficit. I guess this will be the case.
    - dhimes 6y ago
      I haven't heard of it with the flu.
      - bamboozled 6y ago
        You have never had a bad flu and had cognitive trouble during recovery? I had a flu once and lost 6kgs in less than 10 days and I was physically and mentally wrecked for some time.
        dhimes 6y ago
Wintamute 6y ago
Causation !== correlation. An alternative explanation is those more likely to catch COVID-19 are more likely to be a cohort with lower IQ to begin with (e.g. have lower skilled jobs that put them in harms way etc.). Without a before and after IQ test of biologically confirmed COVID-19 patients this is junk.
- deleted 6y ago
  [deleted]
- mattdeboard 6y ago
  IQ tests are absolute junk as a measurement of general intelligence. IQ is a political tool not a scientific one.
  - hawthornio 6y ago
    Is there a better method for measuring general intelligence?
    - mattdeboard 6y ago
      IQ is not a method for measuring general intelligence, so there is no way to answer to your question ("better") without perpetuating the myth that IQ is a method for measuring general intelligence
      - biolurker1 6y ago
        The official American academy of psychologists disagree with you. Also many other sciences such as Cognitive neuroscience etc.
        mattdeboard 6y ago
        I've never heard of the American Academy of Psychologists.
    - canada_dry 6y ago
yasp 6y ago
Nassim Taleb has assured me that IQ is a "pseudoscientific swindle". Imagine my shock, therefore, to see this paper relying on it.
- krona 6y ago
  Taleb doesn't dispute that IQ measures something useful with regards to cognitive ability.
username90 6y ago
Did they test before and after? Looks to me like they just tested after and then controlled for a few factors. The simple explanation would be that people with cognitive deficits are more likely to catch covid, either from being in worse health or from just doing more dumb shit.
acarl005 6y ago
A friend of mine has lingering short-term memory loss months after recovering from covid19. She didn't suffer symptoms too bad during the illness. She didn't go to the hospital.
temptemptemp111 6y ago
Classic bias. Cognitive deficits in people who think they have had COVID-19 (aka believe propaganda & people in white coats) - lower testosterone too!
deleted 6y ago
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Raphmedia 6y ago
I am glad people are finally looking in that direction. A lot of studies and media attention has been on death rates. This is useful at the start of a pandemic but now we need to look towards the future. Most of us will catch Covid-19 at some point in our lives. What will be the outcome of surviving it?
colincooke 6y ago
This preprint, combined with a recently published study on measurable heart damage [1] makes it clear how little we still know about the long term effects of COVID-19. Similar to this pre-print, [1], looked at both hospitalized and non-hospitalized patients (patients with minor/no symptoms who recovered at home), and found potential long term effects. [1] https://jamanetwork.com/journals/jamacardiology/fullarticle/2768916 https://jamanetwork.com/journals/jamacardiology/fullarticle/...
deleted 6y ago
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biolurker1 6y ago
I'll put another hypotheses here. A well known small group of people that are smart and like to take IQ tests and score high took the test and skewed many results mostly because they were not positive and considered baseline.
Corinthian 6y ago
Anecdotally, I've had covid 19 and I hate to say it, but it is taking me longer to gather my thoughts at present. My ability to sum up the correct word I need seems to have really suffered. I understand tiredness is a longer term effect of covid, so I'm hoping it's that. I didn't suffer any breathing difficulties, though I was told my viral count (I think they called it that) was very high. Also, my short sightedness seems to have noticeably got worse. As I said, this is entirely anecdotal. However, I noticed these differences even before I read this article. I am a little worried.

250 points by luu 6y ago

From the conclusion: "The scale of the observed deficits was not insubstantial; the 0.57 SD global composite score reduction for the hospitalised with ventilator sub-group was equivalent to the average 10-year decline in global performance between the ages of 20 to 70 within this dataset. It was larger than the mean deficit of 512 people who indicated they had previously suffered a stroke (-0.40SDs) and the 1016 who reported learning disabilities (-0.49SDs). For comparison, in a classic intelligence test, 0.57 SDs equates to an 8.5-point difference in IQ."

redis_mlc 6y ago
> the hospitalised with ventilator sub-group So this affects almost nobody then, and is probably caused by the sedatives, immobilization and ventilator organ damage, aside from corona.
- fogihujy 6y ago
  Well, the fact that someone was uable to breathe on their own also suggests that the virus may have caused a lack of oxygen to the brain. In such circumstances brain damage is quite likely, and then the disease would indeed be the cause. Fortunately, the group of people that end up on ventilators is not really that large, and I can imagine minor brain damage would still be preferable to death in many of those cases. As a sibling commented, theeffects that won't start to manifest until a year or two has passed are more worrying. There's simply so much we don't know about this virus yet.
  - neuronic 6y ago
    People are unable to worry about or comprehend the effects that happen right NOW. I am a staunch believer in post-viral syndrome as I experienced it first hand following an Epstein-Barr infection (mono) but aside from a handful of researchers nobody cares at all. For most physicians, it isn't even within the realm of possibilities when you come to them with random maladies. Boom, now you have anxiety because that's what they tell you when they don't know shit. There are so many bodily issues that arose after my Epstein-Barr infection, it's not funny at all. I can absolutely lead a normal life and am active and athletic. But things like autoimmune issues, persistent 15-year brain fog (I'd rather call it frosted glass layer) which randomly clears once a month to remind me how nice it is to be able to think straight, or full-body-numbing attacks in the middle of a gas station. The first 5 years after the disease I regularly felt like passing out. Later I just got dizzy and learned to control it using water and temperature changes (cold water in back of your neck!). I still took on the anxiety story and did something against it. It helped me in many ways but not with post-viral syndrome. It's real and it sucks but it's not being taken seriously at all. I am afraid, some COVID survivors are in for a new life which is different in just the right (but minor) ways to drive you insane. Body just doesn't feel the same as before.
    - rtp 6y ago
      It's amazing how people think a virus that lives latently in B cells and epithelial cells, and is strongly associated with various forms of cancer among a big helping of autoimmune disorders, is incapable of causing post-viral syndromes. No, it must be anxiety, of course! EDIT: Just because a disease makes you frustrated because you can't really do anything about it except empathize and listen, doesn't mean you can just slap the anxiety band-aid on it and call it a day.
      - neuronic 6y ago
        Correct, I don't expect doctors to cure me. I expect them to acknowledge that EBV could play a part here. But nope, just anxiety.
    - throwaway1092 6y ago
      > But things like autoimmune issues, persistent 15-year brain fog (I'd rather call it frosted glass layer) which randomly clears once a month to remind me how nice it is to be able to think straight I've been experiencing something similar for the past 5 years: brain fog (frosted glass is a much better way of putting it.) and some short term memory issues. The doctors put me through a battery of tests to find...that they could find no reason for my ailment. Curious to know what if anything has helped you the most. The 'randomly clearing' brain fog for a day happens to me maybe once every 3 months and it's both a blessing and a curse.
      - jokab 6y ago
        Sorry to hear this. I cured mine with a CPAP machine. I had to be tested with apnea twice bc the first one came out ok but i wasnt convinced. In any case, i hope you feel better
        throwaway1092 6y ago
        Thanks - already had/have a CPAP machine, so unfortunately that's not it.
    - 6y ago
- ghufran_syed 6y ago
  Not sure why you’re getting downvoted - here’s a page about post-intensive care syndrome, on the website of the society for critical care medicine, that’s concordant with what you said: https://www.sccm.org/MyICUCare/THRIVE/Post-intensive-Care-Syndrome https://www.sccm.org/MyICUCare/THRIVE/Post-intensive-Care-Sy...
  - noja 6y ago
    > Not sure why you’re getting downvoted I think he overlooked that the people were hospitalized and on ventilators because they had covid.
    - xd 6y ago
      But it's still an effect of the treatment. If you perform a study on people whom have been ill you're going to get results that show all the symptoms of illness.. the study could have been done with any illness and likely show cognitive decline.
      - shultays 6y ago
        symptoms of illness is the illness itself. Ignoring these symptoms of covid or results of the treatment is saying something like "bullets don't kill people, it ruptures blood vessels and you die due to loss of blood"
        srtjstjsj 6y ago
        You misunderstand the ambiguous wording. If you study only includes people with an illness, the illness itself is a confounder. The point is that if you have a non-ICU covid case, this research is unlikely to apply.
        jrumbut 6y ago
        It feels like we didn't read the same article, they break down numbers for people on ventilators but also hospitalized, non-ventilator patients all the way down to those who received no particular care. The findings were concerning to anyone who had it, they also mention cases where the cognitive deficit was the first reported symptom.
- xd 6y ago
  Also, I had a brief look over the paper but couldn't find anything to control for isolation since lockdown .. surely this would of had an effect on peoples cognition. On a side note, maybe it's just me but I keep seeing comments that don't follow a "politically" accepted view point, being down vote like yours.
  - w_t_payne 6y ago
    Maybe it's because this whole situation has been ridiculously politicized, to the point where it's difficult to have a rational fact-based discussion.
    - hejja 6y ago
      ...about anything. not just covid.
      - EForEndeavour 6y ago
        That's exactly what someone with your political beliefs would say!!
  - deleted 6y ago
    [deleted]
  - jmull 6y ago
    I don't know why people downvote things, but in this case I would hope it's because the previous comment was pretty superficial. Whether the covid causes cognitive decline through causing the use of a ventilator, sedatives, and immobilization or through some other mechanism still means it causes cognitive decline. So there's a basic logic flaw. Also, quite a large number of people have been put on ventilators due to covid-19, not "almost nobody". That's just an incorrect assertion. You'd like to attribute the downvoting to politics, but given the quality issues, I think that's a hard claim to support.
  - api 6y ago
    If isolation with a net connection for a few months dropped multiple IQ points, then all the shut-ins who do nothing but hang around on the Internet all day would be losing multiple tens of IQ points a year and would be functionally disabled by now.
- regularfry 6y ago
  The error bars overlap with the "hospitalised without ventilation" group. There's probably something else going on, and the authors do call out the known cognitive effects of hypoxia.
- nradov 6y ago
  There is some evidence that anesthetics can cause cognitive impairment. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6443620/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6443620/
  - kube-system 6y ago
    I was under the impression, at least as it pertained to the elderly, that GA is commonly known to be a significant risk.
    - nradov 6y ago
      Any type of long hospital stay frequently causes delirium among the elderly. GA makes it worse. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3065676/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3065676/
- simonh 6y ago
  Most of the impact seems to occur even without serious symptoms: >bio-positive cases who reported being ill with no breathing difficulties showed a 0.32SD magnitude cognitive deficit. My wife's hospital was full to the corridors with 'almost nobody's.
- paradox242 6y ago
  As other have already commented, they have already considered your theory in their analysis: "Consequently, the observation of post-infection deficits in the subgroup who were put on a ventilator was not surprising. Conversely, the deficits in cases who were not put on a ventilator, particularly those who remained at home, was unexpected." This effect on those hospitalized is not the primary thrust of their paper. Instead it was the observed effects on those who were not hospitalized or had mild to no respiratory symptoms. They raise many possibilities about why this may be the case and only assert that this effect at least proceeds into the recovery phase. I did not read any claims about this being permanent, broadly speaking.
- biolurker1 6y ago
  As many previous comments said, the article includes mild disease
st1x7 6y ago
Reduction equivalent to the cognitive decline of aging 10 years and larger than the cognitive decline of suffering a stroke? Sounds pretty substantial to me.
- minitech 6y ago
  “not insubstantial” :)
  - dempseye 6y ago
    This is a very English way of expressing oneself.
    - taneq 6y ago
      Well it's not unEnglish.
      - metalliqaz 6y ago
        "inflammable means flammable?"
        solarkraft 6y ago
        "all but"
    - deleted 6y ago
      [deleted]
    - julianlam 6y ago
      I also used to find this disturbing, but the way I have explained this to myself is -- Insignificant < 25% Not insignificant 25-50% Not significant 50-75% Significant > 75% Of course for each individual situation the numbers vary, and I use them simply to demonstrate that it's a matter of degrees, and not as binary as you may expect a typical "not" to be. It is the only double negative I have come to find useful.
sokoloff 6y ago
It’s equally as surprising to me the suggestion that the average decline in IQ from a stroke would be only 6 points or so.
- srtjstjsj 6y ago
  It's an average. Strokes can be very small and localized.
- treeman79 6y ago
  Varies a lot. I get a lot of minor strokes if I skip blood thinners for a week or so. At peak I’m a highly effective programmer. If I’ve had one recently, a “for loop” is a challenging concept. After a few days to weeks I’ll be back to near normal. Some symptoms last longer. Highly active Factor 5 Leiden, so I clot like crazy.
  - hderms 6y ago
    That sounds incredibly difficult. You must be a very strong and intelligent person.
    - treeman79 6y ago
      Thank you, yes beyond challenging. Mostly at this point because I work technical jobs and have no idea how to step down to lower role where periodic reduced intelligence is less of an issue.
- gen220 6y ago
  The impact of a stroke varies a lot with the kind of stroke, and the proximity of quality treatment. An awful stroke speedily treated by top doctors has the chance of imparting basically no change to cognitive function. Of the same token, not-the-worst strokes with mediocre care can ruin one's capacity to work. It's a really complicated medical event, with high variance in outcome. Strokes suck.
mrfusion 6y ago
I’d be curious to see this compared to people hospitalized on ventilators for other diseases. You’re not in good shape at that point and I’d expect all kinds of problems.
- usrusr 6y ago
  Does it matter though? The answer certainly depends on the context of the question: do we just want to assess the risks more precisely than the dead/alive boolean? No, it doesn't matter. Do we want to increase humanity's knowledge about how the virus affects our bodies? Yes, absolutely, if it's worse than standard damage of respirator episodes we'll want to know the "mechanisms" that we causing that extra damage.
  - mrfusion 6y ago
    If we’re being asked to give up our way of life, keep children out of school, damage mental health, give up essential freedoms. Then yes, I’d like to see it compared to existing diseases we’ve been living normally alongside for centuries!
- ineedasername 6y ago
  It's not (just) a matter of whether or not Covid is worse than other serious illnesses. It's that whatever existed already, Covid adds on top of that. So if there were X people that experienced significant health problems before, now there are X + Covid.
cltby 6y ago
I'm certainly not accusing you of this personally, but it's curious how selectively IQ is accepted/denied on this site. It's real enough for the purposes of covid policy, lead abatement, or whatever other fashionable environmental intervention. In just about every other case, flat out denialism.
- salicideblock 6y ago
  The general concern with IQ when used for policymaking, or with standardized "intelligence" tests in general, is that they can fail to account for environmental or cultural factors across individuals or populations. In both cases of covid and lead effects, the effect can be measured on the same population, and/or controlled for proxies of those factors (see "when controlling for age, gender, education level, income, racial-ethnic group and pre-existing medical disorders" in the article. So the general concern with the metric can be excluded.
  - cltby 6y ago
    Psychologists are just as adept at "controlling for age, gender, education level, income, racial-ethnic group." The validity of IQ was first established using within-group comparisons.
- bitdizzy 6y ago
  IQ is somewhat effective as a diagnostic tool for significant impairment and not much else. Your examples of where it is not contentious are exactly cases where you must measure impairments. Do you want to list some example contexts where you witness "flat out denialism"? In any case there is an important point: The variance of measured IQ for the same individual over time is very high. It's hard to extract a signal for that unless there's a severe effect being measured.
  - cltby 6y ago
    > IQ is somewhat effective as a diagnostic tool for significant impairment and not much else This places exactly zero constraints on the utility of IQ tests. Instead of asking why group A scores higher than group B, I can simply ask why group B is impaired relative to group A. Apparently that should be enough to convince you of the validity of the comparison. > The variance of measured IQ for the same individual over time is very high. The test-retest correlations of IQ batteries are typically in the 0.8-0.9 range. For example, the Wechsler test [1]. This makes IQ probably the single most reliable measure in the social sciences. Perhaps you're referring to the Wilson effect, but that's not at issue here. [1] https://images.pearsonclinical.com/images/pdf/wisciv/WISCIVTechReport2.pdf https://images.pearsonclinical.com/images/pdf/wisciv/WISCIVT...

isoprophlex 6y ago

By no means do I want to detract from the severity of covid infections, but a very important question to answer would be "what's the effect of psychotrauma resulting from illness and hospitalization on cognitive function" I feel that my own cognitive functions have declined as well during the pandemic, due to stress and uncertainty alone. I haven't been infected, mind you.

redis_mlc 6y ago
> "what's the effect of psychotrauma resulting from illness and hospitalization on cognitive function" Ventilators are extremely physically traumatic - those patients are considered to be the sickest in any hospital.
- isoprophlex 6y ago
  It must be hell to have a bunch of suited figures tell you "we're putting you to sleep, hope to see you on the other side"... and then wake up intubated.
  - noneeeed 6y ago
    I believe ITU patients often suffer from psychosis while in treatment and PTSD afterwards. Intensive medical intervention really can be incredibly traumatic for many, over and above the trauma of the illness or injury that put you in ITU.
    - treeman79 6y ago
      For me the treatments went bad, it was being ignored and dismissed at every stage. I had a full on embolism in my lung. Multiple doctors and ER missed it. Kept insisting it was anxiety. Only when skin turned completely white did they reluctantly run an x-ray. Oops. Then I had a reaction to blood thinners. Nurses called me a liar, that no one has a bad reaction. Oh turns out it’s fairly common. Had to let it get to a stroke before they would Change medication. Repeat at every stage.
  - 6y ago

Hnrobert42 6y ago

Make sure you note this has yet to be peer reviewed.

aronpye 6y ago
Here here
- ceilingcorner 6y ago
  * Hear hear I had to look that one up. https://www.grammarly.com/blog/here-here-vs-hear-hear/ https://www.grammarly.com/blog/here-here-vs-hear-hear/
  - diu7sieQuee9jai 6y ago
    They probably meant "here here I'm a peer, I'll review for food." ;)
api 6y ago
Why is this so far down? Of course this is HN where everyone is an expert on everything. Maybe everyone is an epidemiologist today.

pedro-guimaraes 6y ago

Much is still to be discovered about the virus, science only knows the effects after less than 1 year. The question is, what could long-term effects of this virus? (let's in 10-20 years)

hejja 6y ago
true, yet the same can be said of: - any new pharmaceutical - diets (keto, carnivore, etc) - 5g etc point being: modifying behavior due to decade time-horizon unknowns is not really pragmatic.
- murgindrag 6y ago
  It kind of is. If you see a country next to yours building up a massive army, and starting propaganda about your government being evil, that's a good reason to prepare. If we learned of alien life in the galaxy, we might want to prepare too. And with diets and diseases, if something has a short-horizon effect, that's good evidence it might have a long time-horizon effect too. The seriousness with which I respond to COVID19 is mostly due to short time-horizon effects giving strong implications of possible long time-horizon effects. I'm less concerned about the 3% CFR as I am about the larger portion of individuals who might have long-term disability, lower economic output, etc. If that passes, we'll be feeling that for many decades.
- akuchling 6y ago
  It does mean not being very careless about getting infected, and weighs against the idea of going for herd immunity without a vaccine. Here's a Twitter thread listing post-infection syndromes from other vital infections: https://mobile.twitter.com/aetiology/status/1318676570467409922 https://mobile.twitter.com/aetiology/status/1318676570467409...
giantDinosaur 6y ago
This statement is the 'needs more research' of pandemics, and should be banned from public discourse...!
nradov 6y ago

andix 6y ago

Does this study take in account, that people who are hospitalized are probably less healthy than a control group, and maybe already have more cognitive deficits then a control group before getting hospitalized?

regularfry 6y ago
The PDF is available as a preview.
thespoonbends 6y ago
It does not. It mentions "One might posit that people with lower cognitive ability have higher risk of catching the virus. We consider such a relationship plausible; however, it would not explain why the observed deficits varied in scale with respiratory symptom severity.". That is, it attributes that potential causal link as raising incidence of infection (e.g. they may choose to gather in crowds indoors), not as raising the impact of infection. Either way, as a cross-sectional study, it doesn't establish causation, but may be a smoking gun.

cedex12 6y ago

On the subject of side/long term effects of covid: I've heard, second-hand from doctors/physicians, that the long term effects of covid are not necessarily that bad compared to e.g. the flu. The argument being that: 1. covid has been one of the most studied viruses of this kind, so that you have good chances of stumbling upon lots of size effects, simply due to the sheer size of scrutiny. 2. a bad flu also can yield nasty side effects, but we don't talk about that that much. I don't know what to make of that, and since it's second-hand information, I don't even know how true it is… can anyone shed some light on these arguments?

jansan 6y ago
The flu can be nasty. I had a severe case a few years back, and IMO I never fully recovered from it. I consider myself healthy, but I feel that this flu was like getting five years older within two week.
- snazz 6y ago
  (H1N1)pdm09 was the worst illness I've had, both in duration and severity. Interestingly, that flu virus mostly affected younger people. I'd be interested in reading a thorough comparison of H1N1 and SARS-CoV-2.
deleted 6y ago
[deleted]

Liquix 6y ago

Has the mechanism by which the virus affects smell been identified? Could this be related at all? Mysterious neurological symptoms (some of which persist after recovery) are more concerning than the current mortality rate IMO. Great to see studies like this being done.

maxlamb 6y ago
Yes. https://hms.harvard.edu/news/how-covid-19-causes-loss-smell https://hms.harvard.edu/news/how-covid-19-causes-loss-smell
- srtjstjsj 6y ago
  More precisely, yes then no. Yes the smell effect is studied, no it's not neurological.

kmm 6y ago

13050 people report having had covid, but only 361 had had a positive test? How reliable is it that those without a test actually had covid? What if people with lower cognitive ability are more likely to falsely report having had it. > Only a small proportion (0.76%) of participants reported having residual symptoms, Unless I'm misunderstanding something, it seems wrong to calculate that rate over all participants. Someone reporting not being ill can by definition not have residual symptoms. Correcting for that, the proportion with residual symptoms is 4.7%

NumberCruncher 6y ago
> What if people with lower cognitive ability are more likely to falsely report having had it. And that's why we generally shouldn't base studies on self reported data. If you had the opportunity to compare self reported data to empiric data (measured, tracked, etc.) you wouldn't believe self reported data any more, because it's heavily biased. BTW I am pretty sure we could observe significant cognitive deficits by people abducted by aliens as well...
Out_of_Characte 6y ago
"Someone reporting not being ill can by definition not have residual syptoms" Ofcourse they can. This is trivially proven by the fact that alot of people lose their sense of smell after a covid infection. Even mostly asymptomatic people have reported this. "It’s not uncommon for upper respiratory infections such as the common cold or flu to affect our senses of smell and taste. In fact, it’s estimated that a temporary loss of smell happens in over 60 percent of colds and sinus infections." This is why self-reporting is a different ball-game, I (used) to not consider myself 'sick' and symptomatic if I had a minor flu or cold. One can most definitely report 'not being ill' from coronavirus and suffer residual symptoms. https://www.healthline.com/health/coronavirus-loss-of-taste-loss-of-smell#an-early-symptom https://www.healthline.com/health/coronavirus-loss-of-taste-...
- kmm 6y ago
  If you look at the study you'll find that of the 71235 people who reported not being ill, exactly 0 have residual symptoms. I'm assuming selecting the option would have been in impossible in the form. If you have (or think you have) a residual symptom of covid, by definition you must have had it, or think you had it. "Ill" here simply means having contracted the virus.

rodolphoarruda 6y ago

I would be nice if the HN link could reflect the wording found in the article's Abstract: "Case studies have revealed neurological problems in severely affected COVID-19 patients." By adding "severely affected" to the context the authors set an important scope of analysis to their study.

doktrin 6y ago
That's not their scope of analysis, that's just the introductory sentence. It's meant to reflect on the existing body of knowledge prior to their study. To paraphrase, it's essentially saying "this is what we know already, and here is what we're adding to the body of knowledge with this study" As always, it's best to read the source material directly but these are relevant excerpts from the abstract : "Case studies have revealed neurological problems in severely affected COVID-19 patients. However, there is little information regarding the nature and broader prevalence of cognitive problems post-infection or across the full spread of severity... ...People who had recovered, including those no longer reporting symptoms, exhibited significant cognitive deficits when controlling for age, gender, education level, income, racial-ethnic group and pre-existing medical disorders. They were of substantial effect size for people who had been hospitalised, but also for mild but biologically confirmed cases who reported no breathing difficulty." The last part directly contradicts the idea that this study is limited in scope to severe cases.

HoverSausage 6y ago

The study says "They (significant cognitive deficits) were of substantial effect size for people who had been hospitalised, but also for mild but biologically confirmed cases who reported no breathing difficulty." So according to that study, it doesn't appear to be from ventilators if the effect is also seen in mild cases. Or am I reading it wrong?

cpncrunch 6y ago
The effect for non-hospitalised was only around 0.1 SD, so quite small.

baxtr 6y ago

What I’m wondering: people talk about long term effects and we have 9-10 months of data. I remember I had a cold couple of years back and couldn’t taste nor smell for 3 months or so. What about long term effects for people who have gone through other diseases like the flu for example?

flattone 6y ago
Also what about things like haircuts. And other stuff. Burnt toast. Hang nails. I apologize. I never get more than 4 hours of Sleep. And this seems like a friendly jab over wanting to compare the flu to a different virus. Pure humor from an also honest place.
djsumdog 6y ago
It's just way to early for us to be talking about "longer term" effects. In my 20s, I remember it took nearly a month to recovery from pneumonia. I was lucky. Another friend of mine got pneumonia from a viral infection and was out three months and had to take an Incomplete on all his classes for the semester. All infections have the potential for permanent effects, but they're often not common. An interesting example is Lymes Disease. We still don't understand long term Lymes, but for some reason, the immune system continues to react long after the infection is gone.

woeirua 6y ago

It seems that if you develop severe respiratory issues with Covid that you’re going to be hypoxic for a long time, and potentially with very low O2 saturations. Under those conditions, I frankly would be surprised if we didn’t see signs of cognitive impairment.

ceilingcorner 6y ago

This is perhaps impossible to test (which shows the fundamental weakness of social science) but I think it's nonetheless relevant: studies like this don't factor in overall societal attitude. I can't be the only one that has felt tired, depressed, and just plain bewildered over the past six months. The pessimistic doomsday mentality affects everyone, even if you don't actually get the virus. If I took an IQ test today, I bet I would fare worse than pre-COVID (and I haven't gotten it.)

spuz 6y ago
They are comparing test results of people who reported having a positive covid-19 test vs those that reported no positive test or symptoms. The timing of the study should not be a factor.
- ceilingcorner 6y ago
  Good point. Thanks for the info.

fasteo 6y ago

A quick Google search reveals that cognitive deficit seems to be a common consequence in any critically ill patient, not just Covid-19 This study[1] of just one example: Cognitive dysfunction is an important long-term complication of critical illness associated with reduced quality of life, increase in healthcare costs, and institutionalization And the numbers are certainly high: Cognitive impairment was identified in 206 (49.9%) patients, 120 (29.1%) patients had mild or moderate cognitive impairment, and 86 (20%) patients had severe cognitive dysfunction. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5316231/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5316231/

simonh 6y ago
Sure as you say critical illness with long term medical effects is known to have this impact. The difference is that, as the abstract points out, substantial cognitive impairment in Covid patients was found even in people who displayed mild symptoms and were never critically ill.
- fasteo 6y ago
  Fair point. I missed that part. Thanks. Now we should also research if viral infections in general have an association to cognitive deficit. I guess this will be the case.
  - dhimes 6y ago
    I haven't heard of it with the flu.
    - bamboozled 6y ago
      You have never had a bad flu and had cognitive trouble during recovery? I had a flu once and lost 6kgs in less than 10 days and I was physically and mentally wrecked for some time.
      - dhimes 6y ago

Wintamute 6y ago

Causation !== correlation. An alternative explanation is those more likely to catch COVID-19 are more likely to be a cohort with lower IQ to begin with (e.g. have lower skilled jobs that put them in harms way etc.). Without a before and after IQ test of biologically confirmed COVID-19 patients this is junk.

deleted 6y ago
[deleted]
mattdeboard 6y ago
IQ tests are absolute junk as a measurement of general intelligence. IQ is a political tool not a scientific one.
- hawthornio 6y ago
  Is there a better method for measuring general intelligence?
  - mattdeboard 6y ago
    IQ is not a method for measuring general intelligence, so there is no way to answer to your question ("better") without perpetuating the myth that IQ is a method for measuring general intelligence
    - biolurker1 6y ago
      The official American academy of psychologists disagree with you. Also many other sciences such as Cognitive neuroscience etc.
      - mattdeboard 6y ago
        I've never heard of the American Academy of Psychologists.
  - canada_dry 6y ago

yasp 6y ago

Nassim Taleb has assured me that IQ is a "pseudoscientific swindle". Imagine my shock, therefore, to see this paper relying on it.

krona 6y ago
Taleb doesn't dispute that IQ measures something useful with regards to cognitive ability.

username90 6y ago

Did they test before and after? Looks to me like they just tested after and then controlled for a few factors. The simple explanation would be that people with cognitive deficits are more likely to catch covid, either from being in worse health or from just doing more dumb shit.

acarl005 6y ago

A friend of mine has lingering short-term memory loss months after recovering from covid19. She didn't suffer symptoms too bad during the illness. She didn't go to the hospital.

temptemptemp111 6y ago

Classic bias. Cognitive deficits in people who think they have had COVID-19 (aka believe propaganda & people in white coats) - lower testosterone too!

deleted 6y ago

[deleted]

Raphmedia 6y ago

I am glad people are finally looking in that direction. A lot of studies and media attention has been on death rates. This is useful at the start of a pandemic but now we need to look towards the future. Most of us will catch Covid-19 at some point in our lives. What will be the outcome of surviving it?

colincooke 6y ago

This preprint, combined with a recently published study on measurable heart damage [1] makes it clear how little we still know about the long term effects of COVID-19. Similar to this pre-print, [1], looked at both hospitalized and non-hospitalized patients (patients with minor/no symptoms who recovered at home), and found potential long term effects. [1] https://jamanetwork.com/journals/jamacardiology/fullarticle/2768916 https://jamanetwork.com/journals/jamacardiology/fullarticle/...

deleted 6y ago

[deleted]

biolurker1 6y ago

I'll put another hypotheses here. A well known small group of people that are smart and like to take IQ tests and score high took the test and skewed many results mostly because they were not positive and considered baseline.

Corinthian 6y ago

Anecdotally, I've had covid 19 and I hate to say it, but it is taking me longer to gather my thoughts at present. My ability to sum up the correct word I need seems to have really suffered. I understand tiredness is a longer term effect of covid, so I'm hoping it's that. I didn't suffer any breathing difficulties, though I was told my viral count (I think they called it that) was very high. Also, my short sightedness seems to have noticeably got worse. As I said, this is entirely anecdotal. However, I noticed these differences even before I read this article. I am a little worried.