Neeck, G, Crofford, L J · Rheumatic diseases clinics of North America · 2000 · DOI
This review examines how hormone systems work differently in people with ME/CFS and fibromyalgia. In ME/CFS, the stress hormone system appears to be underactive, possibly due to problems in the brain. In fibromyalgia, the opposite seems true—the stress hormone system appears overactive, likely as the body's response to chronic pain. Understanding these differences could help explain why these conditions feel so different and might guide better treatments.
This study identifies fundamental biological differences between ME/CFS and fibromyalgia at the neuroendocrine level, suggesting they may require distinct therapeutic approaches rather than shared treatments. Understanding HPA axis dysfunction in ME/CFS could explain cardinal symptoms like fatigue and post-exertional malaise, and may eventually guide development of targeted interventions.
This review does not establish causality—reduced HPA responsiveness in ME/CFS may be secondary to other pathologies rather than primary. The study does not prove that glucocorticoid replacement is ineffective; the authors note that interpreting glucocorticoid trials depends on disputed evidence of positive effects. It does not definitively identify which specific central or peripheral components of the HPA axis are primarily dysfunctional.
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 →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Neeck, G & Crofford, L J (2000). Neuroendocrine perturbations in fibromyalgia and chronic fatigue syndrome.. Rheumatic diseases clinics of North America. https://doi.org/10.1016/s0889-857x(05)70180-0
BibTeX
@article{mecfsatlas-neeck-2000-neuroendocrine-perturbations,
author = {Neeck, G and Crofford, L J},
title = {Neuroendocrine perturbations in fibromyalgia and chronic fatigue syndrome.},
journal = {Rheumatic diseases clinics of North America},
year = {2000},
doi = {10.1016/s0889-857x(05)70180-0},
note = {PubMed: 11084955},
url = {https://www.mecfsatlas.com/evidence/neeck-2000-neuroendocrine-perturbations},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-29. https://www.mecfsatlas.com/evidence/neeck-2000-neuroendocrine-perturbations
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