Long Covid | Corona infection can reduce IQ – memory problems

Fatigue and lack of concentration are well-known symptoms of a corona infection. Now a study has found that intelligence is also decreasing.

The corona pandemic has changed the lives of many people. And for those affected by Long Covid, it’s not over yet. In addition to fatigue and concentration problems, these people also suffer from mental disorders, which many sufferers describe as “brain fog”.

Various studies have already shown that a corona infection can also put strain on the brain. Now British scientists from Imperial College London have found that some people perform worse on cognitive tests after a corona infection.

In the study carried out in August and September 2022, around 110,000 adults were tested online, including people who had a corona infection, long Covid patients and those who were not infected. The tests aimed to measure the cognitive abilities of the participants. Data from the British React study from 2020 was also used. It represents one of the most extensive Covid data collections in the world.

The result of the investigations:

• The differences in cognitive performance between non-infected and infected people were still measurable after a year.
• Corona infected people perform slightly worse on cognitive tests than non-infected people. The difference is in the range of around three IQ points.
• In Long Covid patients, memory and concentration scores were up to six IQ points lower.

Scientists do not know the exact mechanisms as to why the brain structures are affected at all. However, it was noticeable that the effects on memory and thinking skills were particularly worse in the early pandemic phase, with infections with the wild type or the alpha variant. In addition, longer duration of illness and hospital stays reduced intelligence the most.

However, the study authors emphasized three good news: Firstly, the changes are so small for the individual that, according to the authors, they are unlikely to notice them. Statistically, however, they are definitely noticeable with such a large number of participants.

On the other hand, the concentration and memory problems decreased over time. This also applies to those affected by Long Covid once the other symptoms have subsided. And the third good news is that the situation with Omicron has improved significantly and the impairment of brain performance caused by an infection is no longer as severe.

However, the situation is not unimportant or harmless. According to the Ärzteblatt, Ziyad Al-Aly from the Washington University School of Medicine in St. Louis points out that due to the high prevalence of Long Covid, negative consequences for educational levels, work performance, accidental injuries and other activities that require intact cognitive skills are conceivable. The risk of dementia could also be increased in the long term and needs to be further researched.