Systematic ReviewHumann = Over 25,000 patients across 47 studies2026
Prevalence and long-term outcomes of brain fog and cognitive impairment in individuals with long COVID: A systematic review.
Plain-language summary
This systematic review set out to understand how common brain fog and cognitive impairment are in people with long COVID, and how these symptoms play out over time. It pooled data from 47 studies covering over 25,000 patients, looking at differences by gender, vaccination status, and whether people were hospitalized. The review found that brain fog affected 30% and cognitive impairment 25% of long COVID patients, with women, unvaccinated individuals, and those managed outside hospitals showing higher rates. Symptoms tended to persist or even emerge later, pointing to long-term cognitive challenges for some.
Key findings
- 30% of long COVID patients reported brain fog
- 25% showed cognitive impairment
- Women had higher rates than men (34% vs 23% for brain fog; 29% vs 21% for cognitive impairment)
- Unvaccinated individuals had higher rates than vaccinated
- Symptoms persisted or emerged later in follow-up
How to analyze the study yourself
- Study type
- Systematic reviews pool data from multiple studies for a broader picture, but rely on the quality of the included studies.
- Population
- Long COVID patients from various studies, with subgroup analyzes by gender, vaccination status, and hospitalization.
- Funding
- Not reported
- Watch for
- This review found that brain fog and cognitive impairment affect about a third of long COVID patients, with women and the unvaccinated at higher risk. If you are recovering from COVID and notice persistent mental fuzziness, it may be worth tracking your symptoms and discussing them with your doctor.