COVID-19 patients that experienced brain fog 6-8 months ago had remarkably greater levels of quality of life impairment, post-traumatic stress disorder, fatigue, depression, anxiety, and functional difficulties.

A cross-sectional study was conducted to elucidate functional, psychiatric, medical, and neuropsychological correlates of cognitive issues experienced following recovery from acute SARS-CoV-2 infection.

Overall, 60 subjects went through quality-of-life, functional, medical, psychiatric, and neuropsychological evaluations post COVID-19. A comparison was done between subjects (n = 28) enrolled from the community who were not seeking care and the subjects (n = 32) in the clinical group looking for care for cognitive issues in the post-COVID-19 program for post-acute symptoms of  SARS-CoV-2.

For investigating the association with medical, psychiatric, and neuropsychological variables, a subset of subjects underwent serological testing for tumor necrosis factor-α, interleukin-6, and proinflammatory cytokines C-reactive protein.

People reporting cognitive complaints months after acute coronavirus disease exhibited extremely low neuropsychological  test performance compared to people without such symptoms.  Notably, 27% (n = 16) had very low test scores (< second percentile on at least one neuropsychological test) for the whole sample. In tests of processing speed,  memory, executive function, and attention, the clinical group with cognitive complaints scored less when compared to age-adjusted population standards.

Furthermore, the clinical group with cognitive complaints scored substantially greater in the very low range when compared to the non-clinical group (38% vs. 14%). Reduced quality of life and greater levels of functional difficulties, posttraumatic stress disorder, fatigue, anxiety and depression were reported in the clinical group. The scoring in the very low range was anticipated in the logistic regression analysis by subjective cognitive complaints, several medical comorbidities, current depression score, and acute coronavirus symptoms in the fields of executive, language, and memory tasks.

Interleukin-6 was found to be associated with fatigue, medical comorbidities, and acute COVID symptoms. There was an inverse relation between interleukin-6 and executive functional measures. The correlation among C-reactive protein, depression score, and current SARS-CoV-2 symptoms was seen. C-reactive protein was inversely associated with quality of life.

COVID-19 affected numerous neurocognitive domains and thus few people exhibited extremely low neuropsychological test performance months after acute SARS-CoV-2 infection. This extremely low performance was related to subjective cognitive complaints, functional complaints, medical comorbidities, depression, and worse acute coronavirus symptoms.