ABSTRACT
Recent studies indicate that COVID-19 infection can lead to serious neurological consequences in a small percentage of individuals. However, in the months following acute illness, many more suffer from fatigue, low motivation, disturbed mood, poor sleep and cognitive symptoms, colloquially referred to as brain fog. But what about individuals who had asymptomatic to moderate COVID-19 and report no concerns after recovering from COVID-19? Here we examined a wide range of cognitive functions critical for daily life (including sustained attention, memory, motor control, planning, semantic reasoning, mental rotation and spatial-visual attention) in people who had previously suffered from COVID-19 but were not significantly different from a control group on self-reported fatigue, forgetfulness, sleep abnormality, motivation, depression, anxiety and personality profile. Reassuringly, COVID-19 survivors performed well in most abilities tested, including working memory, executive function, planning and mental rotation. However, they displayed significantly worse episodic memory (up to 6 months post-infection) and greater decline in vigilance with time on task (for up to 9 months). Overall, the results show that specific chronic cognitive changes following COVID-19 are evident on objective testing even amongst those who do not report a greater symptom burden. Importantly, in the sample tested here, these were not significantly different from normal after six-nine months, demonstrating evidence of recovery over time.
ABSTRACT
Case studies have revealed neurological problems in severely affected COVID-19 patients. However, there is little information regarding the nature and broader prevalence of cognitive problems post-infection or across the full spread of severity. We analysed cognitive test data from 84,285 Great British Intelligence Test participants who completed a questionnaire regarding suspected and biologically confirmed COVID-19 infection. People who had recovered, including those no longer reporting symptoms, exhibited significant cognitive deficits when controlling for age, gender, education level, income, racial-ethnic group and pre-existing medical disorders. They were of substantial effect size for people who had been hospitalised, but also for mild but biologically confirmed cases who reported no breathing difficulty. Finer grained analyses of performance support the hypothesis that COVID-19 has a multi-system impact on human cognition. Significance statementThere is evidence that COVID-19 may cause long term health changes past acute symptoms, termed long COVID. Our analyses of detailed cognitive assessment and questionnaire data from tens thousands of datasets, collected in collaboration with BBC2 Horizon, align with the view that there are chronic cognitive consequences of having COVID-19. Individuals who recovered from suspected or confirmed COVID-19 perform worse on cognitive tests in multiple domains than would be expected given their detailed age and demographic profiles. This deficit scales with symptom severity and is evident amongst those without hospital treatment. These results should act as a clarion call for more detailed research investigating the basis of cognitive deficits in people who have survived SARS-COV-2 infection.
ABSTRACT
How has the Covid-19 pandemic affected mental health? What are the most common positives and negatives? How do population variables mediate the impact on mood and behaviour? Who is most at risk of adverse consequences? Which pragmatic measures can help? We address these questions in a data-driven manner by applying multivariate, machine-learning and natural-language processing methods to a survey database collected from 376,987 members of the general public. We report that small average changes in mood from pre-to mid-pandemic obfuscate substantial consequences, both positive and negative, for people from particular sub-populations, vocations, circumstances and personality profiles. The coping strategies that people find helpful during the pandemic are correspondingly diverse yet predictable. We propose that by combining psychological, and demographic variables, it is possible to identify individuals who are at most risk of adverse consequences and to extract individually tailored advice from the collective lived experiences of the general population.
