The association between COVID-19 and cognitive performance: A Mendelian randomization analysis.

INTRODUCTION: People with COVID-19 had poorer general cognitive functioning compared to people without COVID-19. The causal link between COVID-19 and cognitive impairment is still unknown. METHODS: Mendelian randomization (MR) is a statistical approach based on genome-wide association studies (GWAS) to construct instrumental variables (IVs) and can effectively bring down the confounding bias of environmental or other disease factors, because alleles are randomly assigned to offspring. RESULTS: There was consistent evidence that cognitive performance was causally associated with COVID-19; this suggests that people with better cognitive performance are less likely to be infected with COVID-19. The reverse MR analysis treating COVID-19 as the exposure and cognitive performance as the outcome demonstrated an insignificant association, indicating the unidirectionality of the relationship. DISCUSSION: Our study provided credible evidence that cognitive performance has an impact on COVID-19. Future research should focus on long-term impact of cognitive performance on COVID-19.