The COVID-19 pandemic is now approaching its third year, with more than 500 million severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases reported globally. Accompanying the ever-increasing number of COVID survivors is a greater appreciation of the long-term consequences of infection. One frequently reported post-recovery symptom is ongoing cognitive impairment, often referred to as “COVID fog” or brain fog, which may affect up to 25% of recovered individuals .
Although most commonly reported following severe cases, COVID fog is also relatively common among those recovered from mild initial symptoms. In addition to impaired concentration and memory, long COVID has also been associated with increased depression, anxiety, fatigue, and disrupted sleep patterns . Given the global prevalence of SARS-CoV-2 and the detrimental impact of such neurological and cognitive impairment, the public health implications are widespread and considerable. In a recent paper published in Cell, Fernández-Castañeda et al. examined the underlying neurological changes associated with COVID fog (Figure 1) , which we briefly touched on in a recent blog post, and review more extensively here.