Is it true that IQ scores decrease in COVID-19 survivors?

Several years have passed since the world first learned of the existence of Covid-19, but there is still much we do not know about the disease and its consequences. Thus, in the first year of the pandemic, a whole bunch of complications were discovered after the infection – increased fatigue, shortness of breath, pain in the chest, loss of smell and headaches. As new variants of SARS-CoV-2 emerged, the effect of the virus on the body had to be reconsidered – as toxicologist Alexey Vodovozov put it, it captures the «carcass» entirely. This means that there is no organ or system that is not affected by covid. The results of recent studies are also not reassuring – scientists from the UK have found that coronavirus has a negative effect on cognitive abilities and contributes to a decrease in IQ by 3-9 points.

Is it true that survivors of COVID-19 have a decrease in IQ? The results of recent studies have shown that survivors of COVID-19 lead to a decrease in IQ. Photo.

The results of recent studies have shown that COVID-19 leads to a decrease in IQ


  • 1 Post-Covid syndrome
  • 2 How does COVID-19 affect intelligence?
  • 3 Lingering fog
  • 4 What next?

Post-Covid syndrome

We have repeatedly talked about the wide variety of consequences of the coronavirus. It is known that symptoms of the disease can persist long after the initial recovery, and the so-called post-Covid syndrome is being talked about more and more often. Typically, symptoms of long-term COVID-19 appear within four weeks of infection and can persist for months or years.

Scientific research has shown that in the period from one to 12 months after infection with Covid, every fifth person aged 18 to 64 years hasat least one disease caused by COVID-19. Among people aged 65 years and older, every fourth person faces the consequences of an infection.

Post-Covid syndrome. Post-Covid syndrome is an extremely common phenomenon. Photo.

Post-Covid syndrome is an extremely common phenomenon

Most often, doctors report such symptoms of post-Covid syndrome as
fatigue, fever, cough, shortness of breath and digestive problems. Many patients also complain of frequent headaches, dizziness, loss of taste and smell, muscle and joint pain, depression and cardiovascular diseases. And this, of course, is not all.

More on the topic: WHO has defined post-Covid syndrome – what is it?

How does COVID-19 affect intelligence?

Earlier, my colleague Andrei Zhukov talked about the truly frightening consequences of Covid on the brain. It turned out that COVID-19 leads to disorders in the brain similar to those that occur with traumatic brain injury. Moreover, the identified disorders persist in post-Covid syndrome, and the decrease in brain activity is equivalent to aging by as much as 20 years.

Now scientists are reporting even more alarming news – The results of work published in The New English Journal of Medicine showed that
SARS-CoV-2 affects cognition and memory. The researchers also found that post-infection patients who had mild Covid experienced mild cognitive impairment equivalent to a 3-point decline in IQ for 1 year or more after recovery. However, in people with a more severe course of the disease (requiring hospitalization), there was a9-point decrease in IQ.

How does COVID-19 affect intelligence? Coronavirus leads to a decrease in IQ by 3-9 points. Photo.

Coronavirus leads to a decrease in IQ by 3-9 points

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The authors of the scientific work note that people with post-Covid syndrome experienced a greater decline in IQ than those whose symptoms disappeared. The greatest deficits in cognitive abilities were associated with memory and reasoning.

The results showed that patients who had COVID-19 performed cognitive tests slowly and with many errors, than those who have not encountered infection. The group with the greatest cognitive deficits were patients who were in intensive care during treatment for COVID-19, says Adam Hampshire of Imperial College London, one of the authors of the new study.

Lingering fog

Although cognitive problems after coronavirus are well known, whether objectively measurable cognitive impairment exists and how long it lasts remains unclear. To dot the i's, the study authors invited 800,000 adult SARS-CoV-2 REACT survivors in the UK to complete an online assessment of cognitive abilities in eight areas. A total of 141,583 participants completed at least one task, and 112,964 completed all eight.

Scientists assessed cognitive performance in SARS-CoV-2 survivors with symptoms lasting at least 12 weeks, regardless whether they disappeared or not, as well as among uninfected study participants. The results showed that, compared with those who had never had COVID-19, those who encountered the virus experienced a decrease in IQ score by 3 points.

Long-term fog. Coronavirus has a negative impact on cognitive abilities. Photo.

Covid-19 has a negative impact on cognitive abilities

This is interesting: Long-term COVID destroys internal organs – why does this happen

In turn, study participants who experienced post-Covid syndrome showed a decrease in IQ by 6 points, and those who were hospitalized in the intensive care unit showed a decrease in IQ by 9 points.

At the same time, as the researchers report, the greatest decline in IQ scores was observed in people infected at the beginning of the pandemic with the original SARS-CoV-2 virus or the B.1.1.7 variant, while those who became ill during the Omicron period had a lower score decline. The authors note that their findings are consistent with other studies suggesting that the link between cognitive impairment caused by COVID-19 weakened as the pandemic progressed.

Long-lasting fog. The study involved 800,000 people who had COVID-19. Photo.

The study involved 800,000 people who had recovered from COVID-19

In patients who recovered from COVID-19 and took part in the new study, there was a decrease in IQ by 3-9 points

  • by 3 points for those who had a mild form of illness
  • by 6 for those who experienced post-Covid syndrome
  • by 9 for those hospitalized in the intensive care unit
The study results also showed that IQ scores among vaccinated subjects who had COVID-19 were lower compared to those who were not vaccinated. «Memory, reasoning, and executive function tasks were among the most sensitive to cognitive differences associated with COVID-19, and performance on these tasks varied by illness duration and hospitalization,», the paper says.

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What's next?

The results are concerning and require further research. Thus, at the time of publication, several unresolved questions remain, including the potential functional consequences of a 3-point decline in IQ and whether cognitive impairment associated with COVID-19 predisposes one to a higher risk of developing dementia later in life.

Better understanding of the biology of cognitive dysfunction following SARS-CoV-2 infection and how best to prevent and treat it is critical to meeting the needs of affected individuals and preserving the cognitive health of the population, say the researchers, who were not involved in the work.< /p>

What's next? The consequences of coronavirus for the brain turned out to be much more serious than previously thought. Photo.

The consequences of coronavirus for the brain turned out to be much more serious than previously thought

Commenting on the study for Medscape Medical News, Jacqueline Becker, a clinical neuropsychologist at the Icahn School of Medicine in New York, noted that «one important caveat» is that the study used an online cognitive assessment tool and thereforethe results should be taken with a «a grain of salt».

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However, the study does have a large sample, and the results are generally consistent with what we have seen in terms of cognitive deficits after COVID-19. It's also likely that the new study «underestimates» the degree of cognitive decline that would be observed across a range of neuropsychological tests. Fortunately, previous research in this area has shown that cognitive abilities generally improve 12 to 18 months after COVID-19. We are talking mainly about disorders of memory, attention and speed of information processing.