COVID-19 infections and cognitive impairment: mechanisms and perspectives.

Severe viral respiratory infections have gained attention in recent years. One aspect is the cognitive impairment that many patients experience either during or following infections, such as COVID-19. The aim of this Journal club is to present and discuss different studies on this topic in the hope of proposing future research questions. The four studies discussed all investigate COVID-19 patients in observational cohorts and the possible association between severe viral respiratory infection and cognitive impairment. Needham et al. and Born et al. investigate the immunological signature of COVID-19 patients to assess dysregulated immune and inflammatory responses and the association with specific biomarkers and delirium diagnosis, respectively. To supplement biochemical associations, Maamar et al. investigated agitation in patients with acute respiratory distress syndrome, while Aarskog et al. designed a study to investigate whether acute hypoxia and hypocapnia could increase the risk of delirium. The studies differ substantially regarding outcomes and methods, and are therefore not entirely comparable. They do, however, exemplify the need for a broader perspective in studies investigating complex problems. Future studies might therefore benefit from combining approaches to better elucidate the full physiological pathway, and not just simplify it or isolate potential causality.