Bretherick, Andrew D, McGrath, Simon J, Devereux-Cooke, Andy et al. · NIHR open research · 2023 · DOI
This large study asked over 17,000 people with ME/CFS about their symptoms, when their illness started, and what health conditions they experience. The researchers found that ME/CFS is not one-size-fits-all: people whose ME/CFS began after an infection (like COVID-19 or glandular fever) reported different patterns of symptoms and other health problems compared to those whose illness started without a clear infection. The study also confirmed that women are more affected by ME/CFS than men, and discovered that women tend to have more additional health conditions alongside ME/CFS.
This study provides the largest systematic characterization of ME/CFS heterogeneity to date, suggesting that future research treating ME/CFS as distinct subtypes (rather than a single condition) may improve our ability to identify underlying biological mechanisms and develop targeted therapies. By demonstrating that infection-type at onset correlates with different symptom patterns and comorbidities, the study supports a more nuanced approach to understanding ME/CFS pathogenesis and potentially identifying subgroup-specific interventions.
This study does not prove that infection causes ME/CFS or that different onset types have different biological mechanisms—it only shows associations in self-reported data. The cross-sectional design cannot establish causation, temporal relationships, or whether observed differences reflect true disease subtypes or variation in symptom reporting and comorbidity recognition. Results are limited to UK participants and may not generalize to other populations.