ICD-10 Diagnoses prior to ME/CFS diagnosis in children and young people suggest potential early diagnostic indicators.
Wirth, Marielle, Haastert, Burkhard, Linnenkamp, Ute et al. · Scientific reports · 2026 · DOI
Quick Summary
This study looked at medical records of young people (ages 6-27) diagnosed with ME/CFS to see what health problems they had in the year before their diagnosis. Researchers found that certain conditions—like fatigue, depression, pain disorders, and post-COVID-19 condition—appeared more often in people who later developed ME/CFS compared to similar young people who didn't develop it. This suggests these earlier diagnoses might be early warning signs or related to ME/CFS development, though the study cannot prove they actually caused ME/CFS.
Why It Matters
Early identification of ME/CFS in young people is challenging, and many patients experience diagnostic delays. This study provides potential diagnostic indicators that clinicians should be alert to when evaluating young patients, particularly those with post-COVID-19 condition, depression, pain disorders, and fatigue. Understanding patterns preceding ME/CFS diagnosis may help improve early detection and support for affected young people.
Observed Findings
Forty-four ICD-10 code classes associated with increased odds of subsequent ME/CFS diagnosis, spanning 13 diagnostic chapters.
Post-COVID-19 condition showed the strongest association with later ME/CFS diagnosis (OR 3.84, 95% CI 2.97-4.98).
Common diagnoses in the year before ME/CFS diagnosis included fatigue, depression, pain disorders, and somatoform disorders (≥10% prevalence; ORs 1.11-2.19).
Rare diagnoses such as fibromyalgia (OR 2.08) and mild cognitive impairment (OR 2.93) showed particularly strong associations despite low prevalence.
Majority of cases were female and aged 18-27 years.
Inferred Conclusions
Multiple diagnostic codes across mental health, respiratory, and musculoskeletal domains in the year preceding ME/CFS diagnosis may serve as early diagnostic indicators.
Post-COVID-19 condition is strongly associated with subsequent ME/CFS diagnosis, suggesting possible mechanistic or diagnostic overlap.
Rare conditions with high specificity (fibromyalgia, mild cognitive impairment) may warrant particular clinical attention as potential ME/CFS precursors.
Remaining Questions
Do these preceding diagnoses represent early manifestations of ME/CFS itself, separate triggering conditions, or misdiagnoses of emerging ME/CFS symptoms?
What This Study Does Not Prove
This study cannot establish causation—having these conditions does not mean someone will develop ME/CFS. The associations observed could reflect early symptoms of ME/CFS being misclassified under other diagnoses, rather than separate conditions triggering ME/CFS. Additionally, the study cannot clarify whether identified conditions preceded ME/CFS onset or emerged simultaneously as early manifestations of the disease itself.
What is the precise temporal relationship between identified conditions and actual ME/CFS symptom onset, versus the formal diagnosis date?
How many individuals with these preceding diagnoses develop ME/CFS versus remain with their original diagnosis, and what distinguishes those who progress?
To what extent do these associations differ by age group, sex, and geographic/socioeconomic factors?