Introduction

To show these changes were specific to COVID and not just related to having a respiratory illness, the scientists also looked at a group of people who had pneumonia. They did not see the same changes, confirming they are related to COVID.

Decreases in brain volume are common to many brain d...

Scientists collected data as part of the UK Biobank database. They looked at brain MRI scans and tests of brain function in 785 volunteers who were assessed before the pandemic. They then compared this to the same data collected three years later, when around half of those participa...

Many people who have had COVID, no matter how mjlfreport feelings of “brain fog”, fatigue, and problems with concentration and memory long after their initial symptoms resolve. These problems, collectively known as 'long COVID', may last for months even after mild infection.

Long COVID is v...

Problems with memory and attention are also frequent for people with these diseases and disorders, indicating mild COVID infection may accelerate brain degeneration. These changes could explain the reported symptoms of long COVID, such as brain fog.

The study did not look at the mechanisms ...

This study also only included people aged 51–81, so we do not know whether these findings are relevant for younger people or children.

The brain changes found in this study were more pronounced in the older participants, so it could be that older people are more susceptible. Another study i...

There were some differences between the groups before COVID, with smaller volumes of areas deep within the brain. However, these were in different brain areas to those affected after COVID.

The scientists also found slightly reduced scores for brain functions of thinking and remembering in...

This study provides the first important information about brain changes in people with mild COVID infection. Until we have all the information, we should be alert but not alarmed at emerging findings.

The group who had mild COVID an average of five months beforehand had thinning of brain tissue in several brain regions, ranging from 0.2% to around 2% compared to their pre-COVID scan (between one and six years of normal brain ageing). Affected brain areas included the parahippocampal gyrus (rel...

So does this study prove all people who have had mild COVID infections will have these same brain changes and long-term brain degeneration? Not necessarily.

There are several important things we still do not know. This includes whether these brain changes will get worse over time, or whethe...