Brain fog is a commonly reported symptom of Covid-19, both during the acute phase of the illness and as part of the condition known as long Covid. It serves as a catch-all term for a range of cognitive and affective impairments, including attention deficits, problems with speaking and memory, dizziness and disorientation, emotional discalibrations, fatigue, depression, and anxiety. Terminologically, brain fog is vague and imprecise, perhaps usefully so. Although it is sometimes mentioned and discussed in the clinical literature on Covid, it is not strictly a clinical term. It belongs instead to a quasi-medical middle ground that exists somewhere between clinical language and googlised self-diagnosis. So it comes from that discursive zone so massively expanded in the past two years that lies at the interface of medicine and mediatised public concern. It is a term of Zoom culture, of hashtagged epidemiology.

My colleague was speaking during one of Melbourne’s lockdowns in 2021, when comparatively few people in Australia had Covid. She certainly didn’t have it. Her Covid brain fog was symptomatic in the cultural rather than the medical sense. What she was referring to were the cognitive effects of working in lockdown and in a collapsing higher education system. The symptoms may have been similar: difficulty concentrating, memory lapses, anxiety, tiredness, and so on. But they were caused not by the novel coronavirus, at least not in any direct sense, but instead by the pressures simply of living – things like employment, and parenthood, and everyday life – over the past two years. I was in another Zoom meeting when a different Melbourne lockdown was announced. As the news filtered through from messaging platforms and other social media, everyone started crying. Perhaps brain fog offers no more than a fuzzy label for this condition. Still, when my colleague used it, I felt that she was naming something real – real enough to cry about on Zoom, at least.

Google Ngram – the favourite tool of the hobby philologist – identifies two key moments in brain fog’s linguistic career up until 2020. The most recent is a steep rise in the frequency with which the term appears in published English-language writing. This rise began in the late 1990s in alternative medicine and self-help, when brain fog started to appear in books on such subjects as hypnotic suggestion, essential oils, the Atkins and the liver detox diets, and holistic approaches to chronic fatigue. More recent titles include The Brain Fog Fix: Reclaim your focus, memory, and joy in just 3 weeks, published in 2016 and rated 4.4 from 745 ratings on Amazon.com. It is surely no coincidence that this was also the period of the increasingly pervasive circulation of neural imaging. From the 1990s, brain fog, although terminologically imprecise, had a set of clear visual correlatives in the public imagination. The term evoked the blurry smudges familiar from neuroimaging and neuroradiology. That grey fogging there: that is the cancer, the stroke, the lesion.

But for all its apparently millennial flavour, the term is much older. Brain fog first entered the language in the 1870s, principally in medical publications. There it tended to be linked to, as a scientific paper presented in New South Wales in 1891 put it, ‘the influence of modern civilization on the production of insanity’. More specifically, brain fog was linked to the mental derangements brought about by literary, educational, and intellectual labours. Case studies included a clergyman who, ‘both in preparing and preaching his sermons … felt as though there was “mist in his brain”’, and an overworked book reviewer ‘who got into a state of brain fog, and broke into poetry’. A chapter on ‘insanity relating to the higher classes’ from 1878 identified brain fog as a condition caused by ‘the excessive cramming’ characteristic of modern schooling, in a passage that would be much quoted by educational reformers in coming decades. Faced with the massive modern expansion of printed knowledge, the brains of intellectual workers, it seemed, had been befogged.

Behind these medical uses lay the second paragraph of Charles Dickens’s Bleak House (1853), which began ‘Fog everywhere’ and continued for another 160 words, no fewer than eleven of which were repetitions of the word ‘fog’. Fog was indeed everywhere in Bleak House: in the atmosphere, in the legal system, in the perceptions and motivations of the characters. It was also everywhere in nineteenth-century literature more generally: recall, for instance, the gothic atmospherics of Edgar Allan Poe, or of the Brontës. Literary historians have shown that Dickens’s fog was just one example of a widespread cultural metaphorisation of meteorology taking place in this period, during which literature was increasingly dedicated to modelling, mediating, and communicating atmospheres. Always implied in this atmospheric turn was that literature – writing, education – might itself be something like an airborne communicable disease. That link, at any rate, was what underwrote the medical designation of brain fog as an occupational hazard of literary life, an atmospheric madness of writing, in the 1870s.

Dickens’s novel was first published in serial form. The pandemic circuits of contemporary brain fog run on newer platforms and accelerated media. But that shift has only heightened the force of a paradox already present when brain fog was first coined in the nineteenth century. Brain fog is how we’ve all got Covid on the brain. It names the impaired cognitive atmospherics of this airborne pandemic. And its fuzziness as a term points to the fuzzy impossibility of writing clearly about our current condition – about what is to be done, and about how we might do it – while sick, or in lockdown, or precariously employed, or isolated, or depressed. Or on Zoom. Brain fog is what makes it hard to think about brain fog right now. Brain fog everywhere.

This article, one of a series of ABR commentaries addressing cultural and political subjects, was funded by the Copyright Agency’s Cultural Fund.