As a study by Oxford scientists has shown, people who have had mild COVID-19 and do not experience any other symptoms of "long covid" may experience deterioration in memory and concentration. These symptoms may persist up to 9 months after a positive test result is obtained.
Cognitive problems that affect the level of concentration, as well as fatigue and problems with memory are characteristic symptoms of the so-called long Covid, i.e. complications after contracting COVID-19, which in some people may persist for a long time after recovery. How widespread and prolonged concentration problems can be in convalescents, researchers in Oxford have studied.
The study included people who had previously tested positive for the coronavirus, but had no other typical symptoms of long Covid. These people were asked to perform exercises to test their memory and cognitive abilities.
Researchers have observed that survivors who have mildly contracted COVID-19 have severely impaired episodic memory over the next six months, i.e. they have less recall of personal experiences. In turn, nine months after infection, these people also saw a greater decline in their ability to maintain attention than in those who did not suffer from COVID-19.
"It is surprising that, although people who had COVID-19 and had no symptoms at the time of the study, they did exhibit reduced ability to concentrate and memory. Our findings reveal that people may experience some chronic cognitive consequences. for many months, "said one of the study authors Dr. Sijia Zhao of the Oxford University Department of Experimental Psychology.
The researchers found that in the subjects of this study, episodic memory and concentration levels largely returned to normal after six and nine months, respectively. Participants also performed well on tests of other cognitive abilities, including working memory and planning.
Stephen Burgess of the MRC Biostatistics Unit at the University of Cambridge noted the small number of people in the study - 136, and added thatit was not randomized. 'However, despite this, the differences between the Covid and non-Covid groups in several of the specific measures of cognitive performance highlighted in this study were striking. Despite the limitations of non-randomized studies, it seems unlikely that these results can be explained by systematic differences between groups that would not be related to Covid infection, Burgess said.