BackgroundThe term ‘brain fog’ is increasingly used colloquially to describe difficulties in the cognitive realm. But what is brain fog? What sort of experiences do people talk about when they talk about brain fog? And, in turn, what might this tell us about potential underlying pathophysiological mechanisms? This study examined first-person descriptions in order to better understand the phenomenology of brain fog.MethodsPosts containing ‘brain fog’ were scraped from the social media platform Reddit, using python, over a week in October 2021. We examined descriptions of brain fog, themes of containing subreddits (topic-specific discussion forums), and causal attributions.Results1663 posts containing ‘brain fog’ were identified, 717 meeting inclusion criteria. 141 first person phenomenological descriptions depicted forgetfulness (51), difficulty concentrating (43), dissociative phenomena (34), cognitive ‘slowness’ and excessive effort (26), communication difficulties (22), ‘fuzziness’ or pressure (10) and fatigue (9). 50% (363/717) posts were in subreddits concerned with illness and disease: including COVID-19 (87), psychiatric, neurodevelopmental, autoimmune and functional disorders. 134 posts were in subreddits about drug use or discontinuation, and 44 in subreddits about abstention from masturbation. 570 posts included the poster’s causal attribution, the most frequent attribution being long COVID in 60/570 (10%).Conclusions‘Brain fog’ is used on Reddit to describe heterogeneous experiences, including of dissociation, fatigue, forgetfulness and excessive cognitive effort, and in association with a range of illnesses, drugs and behaviours. Encouraging detailed description of these experiences will help us better understand pathophysiological mechanisms underlying cognitive symptoms in health and disease.

Stem cell research has attracted much public and biomedical anticipation centred on the possibility of using stem cells to treat various diseases and conditions, but the number of evidence-based therapies is currently limited. Numerous commercial direct-to-consumer (DTC) businesses are nonetheless marketing experimental stem cell therapies online for myriad medical conditions and aesthetic ailments, which has attracted critique due to safety and efficacy concerns. Existing research has largely focused on the problem of unproven therapies and regulatory pathways for addressing it. The proliferation of these experimental products must also be examined, however, in the broader socio-technological context of consumer culture and changing practices of knowledge-making in the digital era. DTC stem cell therapies have emerged as a new biomedical 'lifestyle' product that blurs the boundaries between 'science,' 'medicine,' and 'consumer culture.' In using, conceptualising and marketing stem cells, commercial businesses build on and commercially co-opt alternative epistemic and ontological frames that challenge scientific medicine. They advance promissory narratives about their potential that tap on cultural aspirations around the future of medicine and health. This is key, not only for understanding how and why these therapies have proliferated but also in conceptualising what the 'problem' around them actually is.

Aim: This study examines online enquiries received by two prominent stem cell science initiatives operating in different geographical jurisdictions. Materials & methods: Combined quantitative and qualitative analysis undertaken of internet-based queries (n = 1047) received by Stem Cells Australia and EuroStemCell from members of the public over a two-year period (May 2014–2016). Results: Findings reveal striking similarities between the two datasets and highlight the range of uncertainties, priorities and needs of those seeking information about stem cells online. Conclusion: Sustained and in-depth tailored guidance is needed to effectively meet the diverse stem cell-related information-based needs of communities internationally. Such efforts should be prioritized by regenerative medicine research initiatives and organizations, given the trust and hope diverse publics appear to place in these groups.