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.
If “intelligence” is just the degree/quality of someone’s brain function then your intelligence does drop when your brain function is impaired, and you would expect that to be picked up in an intelligence test.
Culturally we may want to imagine intelligence as something constant and innate to somebody’s soul, but in reality it’s innate to a fragile and fickle organ inside your skull.
Which is also my issue with IQ tests and the relationship of the tests and what they measure. But that changes nothing: IQ tests are not supposed to measure _that_ variability of when you get sick. Or you wake up. Or you are drunk. It makes no sense to use a psychometric test completely out of the context of which it was validated and meant to be used, because then the results are not interpretable. People with that kind of post-covid syndrom have an illness and experience cognitive deficits because of that, but using IQ to measure intelligence in that case when what you actually (want to) measure is brain fog is absurd. That should require a brain fog screening, not an IQ test.
I always assumed it was because there are people born with impaired intellectual abilities, and having some measure of how impaired they are would be significant for things like edibility for benefits and management of their condition (e.g. goals for the school system).
If I do one sober, I have an IQ of 110, if I do it with my ADHD meds, it goes up to 120.
Is that because the meds make me smarter? No, it's because I don't lose attention after 10 minutes of test and can concentrate until the end. However, the numbers imply otherwise.
At some level, IQ tests measure your ability to take IQ tests. So it would make sense that your measured IQ would go up when you're on ADHD meds, since those will obviously have an effect on your ability to take IQ tests.
Why assume it if it's not proven yet? We had crazy assumptions on the way lightning worked, I'm glad we have empirical natural sciences now to counter these "wide spread assumptions".
Wrt covid and IQ. Say that during covid IQs measurably dropped: why says its not the WFH, the fear that was rampant or the mRNA vaccine that was massively injected? There for we need bigger studies, control groups, randomization. All of this is there for good reasons (and a lot of this was skipped in the development of mRNA vaccines for a bad reason: fear).
Zhao et al '24 [0] comes immediately to mind; operating on a radically different set of people and data sets from Al-Aly and the gang, they find substantial differences in simple reaction time between covid and no-covid groups.
It seems we're in a phase of the pandemic where denying long tail effects is going to become more prominent as concerning evidence continues to pile up. The name of the game is still to reduce your infection count as much as possible. Stay safe out there, share aerosols unprotected at your own peril.
[0] https://www.thelancet.com/journals/eclinm/article/PIIS2589-5... "Long COVID is associated with severe cognitive slowing: a multicentre cross-sectional study"
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...
I know there was work recently that found blood tests can find various markers of long covid, I'd like to get this done - but it's not something widely available.
A relative has been getting strange post-viral like symptoms since before Xmas (though no obvious Covid infection), would be great to get them tested too.
'Covid infections associated with IQ drops and years of brain aging, studies suggest'.
You can even remove the 'studies suggest' part in that case to get just 'Covid infections associated with IQ drops and years of brain aging'
The medical grade face mask respirators have electric fans to provide air flow as well to prevent precisely this.
https://bmcinfectdis.biomedcentral.com/articles/10.1186/s128...
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?
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.