SARS-CoV-2 infection can cause the brain to shrink, reduce grey matter in the regions that control emotion and memory, and damage areas that control the sense of smell, a UK study has found.

Previous research has noted that some COVID-19 patients suffer ‘brain fog’, or mental cloudiness, which includes impairment to attention, concentration, speed of information processing and memory.

This latest research confirmed “there is strong evidence for brain-related abnormalities in COVID-19,” according to the Oxford University researchers writing in Nature on Monday.

The effects were even seen in patients who had not been hospitalised with the infection, they said.