Petersen, Marie Weinreich, Wellnitz, Kaare Bro, Carstensen, Tina Birgitte Wisbech et al. · Journal of psychosomatic research · 2025 · DOI
This study looked at how many weeks per year people with functional somatic disorder (FSD)—a condition with persistent physical symptoms that can't be explained by standard medical tests—used welfare benefits compared to people without FSD. Researchers in Denmark tracked about 9,600 people over 14 years and found that people with FSD used significantly more sickness benefits, unemployment benefits, and disability pensions than those without the condition. The findings show that FSD is a seriously disabling condition that affects people's ability to work and support themselves.
This study provides robust population-level evidence that FSD—a diagnosis overlapping with ME/CFS—causes substantial work disability and socioeconomic burden comparable to or exceeding other severe chronic diseases. For ME/CFS patients and advocates, it demonstrates that functional somatic conditions warrant the same recognition, clinical resources, and disability support as conditions with more obvious pathological markers. The findings support the need for earlier diagnosis, validation of patients' experiences, and access to appropriate welfare protections.
The study does not establish whether welfare benefit use is a direct consequence of FSD symptoms, a consequence of diagnostic delay and lack of treatment, or influenced by other unmeasured social and psychological factors. While the study shows association between FSD diagnosis and higher benefit utilization, it does not prove causation or determine whether equivalent FSD cases with better medical support would require fewer benefits. The cross-sectional comparison with other diseases does not account for different healthcare pathways or cultural differences in benefit-seeking behavior.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
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