BACKGROUND

Research into COVID-19-related cognitive decline has focused on individuals who are cognitively impaired following hospitalization for COVID-19. Our objective was to determine whether cognitive decline emerged after the onset of COVID-19 and was more pronounced in patients with postacute sequelae of SARS-CoV-2 infection (PASC).

METHODS

We analyzed longitudinal cognitive data collected during a cohort study of essential workers at midlife that continued through the COVID-19 pandemic. We used longitudinal discontinuity models, a form of causal modeling, to examine the change in cognitive performance among 276 participants with COVID-19 in comparison to contemporaneously-collected information from 217 participants who did not have COVID-19. Cognitive performance across four domains was measured before and after the pandemic. Eligible study participants were those with validated COVID-19 diagnoses who were observed before having a verified COVID-19 infection who survived their initial infection, and for whom post-COVID-19 information was also available.

RESULTS

The mean age of the COVID-19 group was 56.0 ± 6.6 years old, while the control group was 58.1 ± 7.3 years old. Longitudinal models indicated a significant decline in cognitive throughput (β = -0.168, P = .001) following COVID-19, after adjustment for pre-COVID-19 functioning, demographics, and medical factors. Associations were larger in those with more severe COVID-19 and those who reported PASC. Observed changes in throughput were equivalent to 10.6 years of normal aging.

CONCLUSION

Findings from this longitudinal causal modeling study revealed that COVID-19 and PASC appeared to cause clincially relevant cognitive deterioration.