COVID-19 May Be Linked to a Long-Term Decrease in Cognitive Abilities in Hospitalized Patients

Patients who were hospitalized with COVID-19 may have a higher risk of long-term cognitive complications, according to researchers in Denmark who published their findings in JAMA Network Open. Compared to healthy individuals, patients hospitalized with COVID-19 performed worse on a series of cognitive tests and were more likely to suffer from anxiety, depression, or have impaired memory at 6-months post-infection.

“The long-term effects of COVID-19 are associated with more than 200 symptoms, affecting 65 million individuals worldwide,” wrote study authors. “Apart from respiratory symptoms, the most frequent symptoms are related to brain health, including cognitive and mental symptoms.”

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Researchers performed a prospective cohort study of 345 people in Copenhagen, Denmark, to see whether COVID-19 infection was associated with long-term cognitive, psychiatric, or neurological complications. They also evaluated the magnitude and types of complications associated with infection and compared it to patients who were healthy or hospitalized with another illness.

For the study, each of the 3 cohorts—those hospitalized with COVID-19, patients in the hospital for medical conditions of similar severity, and healthy controls—performed cognitive, psychiatric, and neurological tests, and the scores were compared between the 3 groups during an 18-month follow-up period.

Patients hospitalized with COVID-19 had observably reduced cognitive abilities compared to healthy individuals, based on scores from the Screen for Cognitive Impairment in Psychiatry (SCIP) and the Montreal Cognitive Assessment (MoCA) tests. However, impact of the disease on cognition was not significantly worse than what was experienced by patients hospitalized for a different condition of similar severity.

Researchers also found that patients with COVID-19 performed worse than healthy patients on psychiatric and neurological assessments. At 18 months, patients who were hospitalized with COVID-19 were more likely to have a new onset psychiatric diagnosis, fatigue, and impaired olfaction. These patients also had increased reports of anxiety and depression compared to healthy individuals, along with other subjective symptoms “involving memory and sleep between 6-month and 18-month follow-up,” study authors wrote in the article.

However, like the trend of cognition scores, patients with COVID-19 generally did not have worse psychiatric health compared to patients hospitalized for other diseases—they were not significantly more likely to have anxiety or depression. Further, scores on the neurological assessment were fairly similar between patients with COVID-19 or another hospitalized illness;however, those with COVID-19 were more likely to have olfactory dysfunction and impaired executive function.

The authors noted that there are limitations to this study. Some of the primary limitationsincluded long follow-up, different baseline groups, the presence of different strains of COVID-19, and a lack of available cognitive scores associated with COVID-19 prior to the pandemic.

Authors concluded that “brain health after COVID-19 seems overall comparable to that after other diseases of similar severity.”

Reference

Peinkhofer C, Zarifkar P, Christensen RHB. Brain Health After COVID-19, Pneumonia, Myocardial Infarction, or Critical Illness. JAMA Netw Open. 2023;6(12):e2349659. doi:10.1001/jamanetworkopen.2023.49659