Dr Taquet said: 'Both fibrinogen and D-dimer are involved in blood clotting, and so the results support the hypothesis that blood clots are a cause of post-COVID cognitive problems. Fibrinogen may be directly acting on the brain and its blood vessels, whereas D-dimer often reflects blood clots in the lungs and the problems in the brain might be due to lack of oxygen. 'The ultimate goal is to be able to prevent and reverse the cognitive problems seen in some people after COVID-19 infection. This study provides some significant clues.”The participants involved in this research are part of the UKRI funded PHOSP-COVID (Post-hospitalisation COVID-19) study, led by University of Leicester. The full paper, 'Acute blood biomarker profiles predict cognitive deficits 6 and 12 months after COVID-19 hospitalization', can be read in Nature Medicine.