Covid New studies says Covid lowers IQ and lead to the equivalent of 7 to 20 years of brain aging

[Maciamo]

If true, that would be terrible news for the world as a whole. Brain fog, poor memory and lower IQ would significantly affect the economy, reduce scientific research, and more generally cause a diminution of well-being and productivity. It could also lead to the election or worse politicians, who in turn would take worse decisions for the world.

The Conversation: Mounting research shows that COVID-19 leaves its mark on the brain, including with significant drops in IQ scores

"From the very early days of the pandemic, brain fog emerged as a significant health condition that many experience after COVID-19.

Brain fog is a colloquial term that describes a state of mental sluggishness or lack of clarity and haziness that makes it difficult to concentrate, remember things and think clearly.

Fast-forward four years and there is now abundant evidence that being infected with SARS-CoV-2 – the virus that causes COVID-19 – can affect brain health in many ways.

In addition to brain fog, COVID-19 can lead to an array of problems, including headaches, seizure disorders, strokes, sleep problems, and tingling and paralysis of the nerves, as well as several mental health disorders.

A large and growing body of evidence amassed throughout the pandemic details the many ways that COVID-19 leaves an indelible mark on the brain. But the specific pathways by which the virus does so are still being elucidated, and curative treatments are nonexistent.
[...]
Now, two new studies published in the New England Journal of Medicine shed further light on the profound toll of COVID-19 on cognitive health.

"Here are some of the most important studies to date documenting how COVID-19 affects brain health:

• Large epidemiological analyses showed that people who had COVID-19 were at an increased risk of cognitive deficits, such as memory problems.
• Imaging studies done in people before and after their COVID-19 infections show shrinkage of brain volume and altered brain structure after infection.
• A study of people with mild to moderate COVID-19 showed significant prolonged inflammation of the brain and changes that are commensurate with seven years of brain aging.
• Severe COVID-19 that requires hospitalization or intensive care may result in cognitive deficits and other brain damage that are equivalent to 20 years of aging.
• Autopsy studies of people who had severe COVID-19 but died months later from other causes showed that the virus was still present in brain tissue. This provides evidence that contrary to its name, SARS-CoV-2 is not only a respiratory virus, but it can also enter the brain in some individuals."

[...]
Drops in IQ

"Most recently, a new study published in the New England Journal of Medicine assessed cognitive abilities such as memory, planning and spatial reasoning in nearly 113,000 people who had previously had COVID-19. The researchers found that those who had been infected had significant deficits in memory and executive task performance.

This decline was evident among those infected in the early phase of the pandemic and those infected when the delta and omicron variants were dominant. These findings show that the risk of cognitive decline did not abate as the pandemic virus evolved from the ancestral strain to omicron.

In the same study, those who had mild and resolved COVID-19 showed cognitive decline equivalent to a three-point loss of IQ. In comparison, those with unresolved persistent symptoms, such as people with persistent shortness of breath or fatigue, had a six-point loss in IQ. Those who had been admitted to the intensive care unit for COVID-19 had a nine-point loss in IQ. Reinfection with the virus contributed an additional two-point loss in IQ, as compared with no reinfection.
[...]
To put the finding of the New England Journal of Medicine study into perspective, I estimate that a three-point downward shift in IQ would increase the number of U.S. adults with an IQ less than 70 from 4.7 million to 7.5 million – an increase of 2.8 million adults with a level of cognitive impairment that requires significant societal support."

 

[Vallicanus]

If true, that would be terrible news for the world as a whole. Brain fog, poor memory and lower IQ would significantly affect the economy, reduce scientific research, and more generally cause a diminution of well-being and productivity. It could also lead to the election or worse politicians, who in turn would take worse decisions for the world.

The Conversation: Mounting research shows that COVID-19 leaves its mark on the brain, including with significant drops in IQ scores

"From the very early days of the pandemic, brain fog emerged as a significant health condition that many experience after COVID-19.

Brain fog is a colloquial term that describes a state of mental sluggishness or lack of clarity and haziness that makes it difficult to concentrate, remember things and think clearly.

Fast-forward four years and there is now abundant evidence that being infected with SARS-CoV-2 – the virus that causes COVID-19 – can affect brain health in many ways.

In addition to brain fog, COVID-19 can lead to an array of problems, including headaches, seizure disorders, strokes, sleep problems, and tingling and paralysis of the nerves, as well as several mental health disorders.

A large and growing body of evidence amassed throughout the pandemic details the many ways that COVID-19 leaves an indelible mark on the brain. But the specific pathways by which the virus does so are still being elucidated, and curative treatments are nonexistent.
[...]
Now, two new studies published in the New England Journal of Medicine shed further light on the profound toll of COVID-19 on cognitive health.

"Here are some of the most important studies to date documenting how COVID-19 affects brain health:

• Large epidemiological analyses showed that people who had COVID-19 were at an increased risk of cognitive deficits, such as memory problems.
• Imaging studies done in people before and after their COVID-19 infections show shrinkage of brain volume and altered brain structure after infection.
• A study of people with mild to moderate COVID-19 showed significant prolonged inflammation of the brain and changes that are commensurate with seven years of brain aging.
• Severe COVID-19 that requires hospitalization or intensive care may result in cognitive deficits and other brain damage that are equivalent to 20 years of aging.
• Autopsy studies of people who had severe COVID-19 but died months later from other causes showed that the virus was still present in brain tissue. This provides evidence that contrary to its name, SARS-CoV-2 is not only a respiratory virus, but it can also enter the brain in some individuals."

[...]
Drops in IQ

"Most recently, a new study published in the New England Journal of Medicine assessed cognitive abilities such as memory, planning and spatial reasoning in nearly 113,000 people who had previously had COVID-19. The researchers found that those who had been infected had significant deficits in memory and executive task performance.

This decline was evident among those infected in the early phase of the pandemic and those infected when the delta and omicron variants were dominant. These findings show that the risk of cognitive decline did not abate as the pandemic virus evolved from the ancestral strain to omicron.

In the same study, those who had mild and resolved COVID-19 showed cognitive decline equivalent to a three-point loss of IQ. In comparison, those with unresolved persistent symptoms, such as people with persistent shortness of breath or fatigue, had a six-point loss in IQ. Those who had been admitted to the intensive care unit for COVID-19 had a nine-point loss in IQ. Reinfection with the virus contributed an additional two-point loss in IQ, as compared with no reinfection.
[...]
To put the finding of the New England Journal of Medicine study into perspective, I estimate that a three-point downward shift in IQ would increase the number of U.S. adults with an IQ less than 70 from 4.7 million to 7.5 million – an increase of 2.8 million adults with a level of cognitive impairment that requires significant societal support."

If all this is true then it may explain politicians around the world.

 

[Maciamo]

If all this is true then it may explain politicians around the world.

Yes, surely. Although I think the trend predated Covid-19.

 

[Gao1111]

The strange thing is that I never got Covid, none of my family or relatives, I even traveled in 2020, went to Chengdu to work on a project, nothing

 

[Maciamo]

The strange thing is that I never got Covid, none of my family or relatives, I even traveled in 2020, went to Chengdu to work on a project, nothing

Almost everybody got Covid. Even if you didn't have any symptoms it doesn't mean that you didn't get it. According to a meta-analysis of 38 studies 44% of the infected people remained asymptomatic throughout the infection.

It's hard to tell exactly the percentage of the population in each country that was infected by covid-19 because in most countries many people didn't get tested either because they didn't have the opportunity (in poorer or rural area) or they didn't want to (in many richer countries). In a country like France where many people did get tested, there were officially 40 million cases for population of 65 million, which is almost 2/3 of the population. But if 44% of the infected people were asymptomatic and most of them didn't feel the need to get tested, the infection rate could well be close to 100%.

That's why these new studies are so concerning. It would mean that everybody lost IQ points since the Covid-19 pandemics, and everyone's brain is older than it should be.

I just wonder if infected but asymptomatic people fall in the category of "mild Covid". The article isn't clear about that.

 

[norbert]

The entire pandemic was a criminal enterprise, from the outbreak (which WAS a lab leak) to the way it was handled, including the enforcement of a rushed jab, resulting in many additional deaths and permanent injuries. So if this study is right, who is to blame? The people who refuse to get vaccinated (the jab doesn't prevent an infection but the symptoms from becoming terminal) or the perpetrators who were running Wuhan and similar labs where naturally occuring virus strains like SARS were weaponised? An embarrassing affair to both the US and China, the partners in crime, which Russia keeps silent about for the sake of its alliance with the latter. It is doubtful whether the COVID pandemic is ever going to be fully examined. Millions have died, civil rights and social relationships damaged. And not to forget the greatest wealth transfer in history that occured during the pandemic. And now, the oil industry is making profits like never before, using the Ukraine war as an excuse. At times, the pandemic felt like an exercise in which the elites wanted to find out how the populations they govern would react to the sudden loss of freedoms and civil rights during a state of emergency like war. Yeah, I may be reading too much into all this but I'm appalled at the overall indifference of the so-called civil society. The elites are not afraid of the people. They don't feel accountable and haven't for a long time, so they do whatever they want because we let them. Should we ever wake up in a major global war, impoverished, sick and completely disenfranchised, we have ourselves to blame. If the study is right, it hasn't discovered anything new.

 

[Maciamo]

I had a quick look at the two studies (Petersen et al. 2023 and Michael et al. 2024) that mentioned brain inflammation and cognitive deficits equivalent to 7 and 20 years of brain ageing. The first study on the tested non-vaccinated people and does not mention if asymptomatic people also suffered from increased brain ageing.

In this case–control study, we demonstrate that non-vaccinated individuals recovered from a mild to moderate severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection show significant alterations of the cerebral white matter identified by diffusion-weighted imaging, such as global increases in extracellular free water and mean diffusivity. Despite the observed brain white matter alterations in this sample, a mild to moderate SARS-CoV-2 infection was not associated with worse cognitive functions within the first year after recovery.

Their wording is not very clear as whether the brain ageing was temporary and disappeared after recovery or not. If it is temporary then it is not such a big issue. From the article in The Conversation I understood that anybody infected with mild to moderate Covid-19 (and presumably also asymptomatic people) would suffer permanent brain alterations and premature brain ageing.

It wouldn't be surprising that someone struggling with a moderate to severe infection (be it Covid-19 or something else) would to be able to think less clearly than when they are feeling well. I've taken many IQ tests in my life and I know that I can get worse results just if I'm tired because I didn't sleep well the night before, or if I'm feeling under the weather. So it would not even be news to say that patients suffering from long Covid performed worse in cognitive tasks than before they were ill. What I want to know is whether people who had asymptomatic Covid or mild Covid symptoms also had decreased cognitive functions one or several years after the infection occurred. That would be (bad) news. But the studies do not say anything about this.

The other study (Hampshire et al. 2024) on cognition and memory says that people with persistent symptoms had larger cognitive deficits, which is again completely expected. But they did find minor cognitive deficits also in participant who had completely recovered from Covid. They're just not sure whether this is permanent or not.

In a multiple regression analysis, participants who had recovered from Covid-19 in whom symptoms had resolved in less than 4 weeks or at least 12 weeks had similar small deficits in global cognition as compared with those in the no–Covid-19 group, who had not been infected with SARS-CoV-2

In a comparison of the group that had unresolved persistent symptoms with the no–Covid-19 group, memory, reasoning, and executive function tasks were associated with the largest deficits

Longer-term persistence of cognitive deficits and any clinical implications remain uncertain.

On the other hand, this study clearly shows that even asymptomatic people also suffered from cognitive deficits after the infection had cleared.