Long Covid ‘brain fog’ equivalent to ageing 10 years, shocking study finds

The study included more than 5,100 participants from the Covid Symptom Study Biobank.

The “brain fog” symptom associated with long Covid is equivalent to ageing 10 years, researchers suggested. A study by King’s College London investigated the impact of Covid-19 on memory and found that cognitive impairment was the highest in individuals who had symptoms for more than three months. The study was published by The Lancet.

An illustration of the novel coronavirus seen next to a health care worker at a Covid-19 testing centre in New Delhi.

“The fact remains that two years on from their first infection, some people don’t feel fully recovered and their lives continue to be impacted by the long-term effects of the coronavirus. We need more work to understand why this is the case and what can be done to help,” Claire Steves, a professor of ageing and health at King’s College, said.

The study included more than 5,100 participants from the Covid Symptom Study Biobank and were reached out through a smartphone app. Using 12 cognitive tests that measured speed and accuracy, researchers examined working memory, attention, reasoning and motor controls between two periods- 2021 and 2022.

In the first cohort of 3,335 participants during July and August 2021, researchers found lower cognitive scores in individuals with positive Covid-19 infections. The deficits were comparable to the effect of “an increase in age of approximately 10 years, or exhibiting mild or moderate symptoms of psychological distress”, it found.

The study found no cognitive impairment for individuals who reported full recovery from coronavirus, study’s lead author Dr Nathan Cheetham said.

“This study shows the need to monitor those people whose brain function is most affected by Covid-19 to see how their cognitive symptoms continue to develop and provide support towards recovery,” Dr Nathan Cheetham explained.