Cognition and Memory after Covid-19 in a Large Community Sample

Area of Science:

• Neurology
• Infectious Diseases
• Public Health

Background:

• Cognitive symptoms are frequently reported after coronavirus disease 2019 (Covid-19).
• The existence and duration of objectively measurable cognitive deficits post-Covid-19 are not well-established.

Purpose of the Study:

• To investigate objectively measurable cognitive deficits in individuals after Covid-19 infection.
• To determine if persistent symptoms correlate with cognitive impairments.
• To assess the impact of different Covid-19 variants and hospitalization on cognitive function.

Main Methods:

• An online cognitive assessment was administered to 112,964 participants in England who had recovered from Covid-19 or had no confirmed infection.
• Global cognitive scores were estimated across eight tasks, with a focus on executive functioning and memory.
• Multiple regression and propensity-score-matching analyses were used to compare cognitive performance between groups.

Main Results:

• Participants with unresolved persistent symptoms post-Covid-19 exhibited larger global cognitive deficits compared to those without Covid-19.
• Cognitive deficits were more pronounced following infection with earlier SARS-CoV-2 variants (e.g., B.1.1.7) and after hospitalization.
• Memory, reasoning, and executive function tasks showed the largest deficits, weakly correlating with self-reported brain fog or memory issues.

Conclusions:

• Resolved persistent symptoms after Covid-19 were associated with cognitive function similar to shorter-duration Covid-19, which itself showed small deficits.
• Longer-term persistence of cognitive deficits and their clinical significance require further investigation.
• No adverse events were reported during the study.