Oliveira, Carlos R, Jason, Leonard A, Unutmaz, Derya et al. · Frontiers in medicine · 2022 · DOI
This study compared people with Long COVID (PASC) to people with ME/CFS, conditions that cause similar symptoms like fatigue and brain fog. Over one year, people with Long COVID showed improvement in five key symptoms including fatigue and post-exertional malaise, while people with ME/CFS did not improve. The researchers used a symptom questionnaire to track changes and found that Long COVID and ME/CFS look similar at first, but Long COVID appears to follow a different course.
Understanding whether Long COVID and ME/CFS are distinct entities or the same condition has critical implications for diagnosis, treatment, and prognosis. This study suggests that Long COVID may follow a different recovery trajectory than established ME/CFS, potentially informing early intervention strategies to prevent Long COVID progression to chronic ME/CFS. The ability to track symptom changes using the DSQ provides clinicians with a tool to monitor disease course and treatment response.
This study does not establish causal mechanisms explaining symptom improvement in Long COVID or why ME/CFS patients do not recover similarly. The significant recruitment time gap (2017 vs 2021) and different cohort sources make it difficult to determine whether observed differences reflect disease biology versus temporal, environmental, or demographic factors. The study cannot definitively prove that Long COVID and ME/CFS are fundamentally different conditions, only that their natural histories appear different in these cohorts.
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
Oliveira, Carlos R, Jason, Leonard A, Unutmaz, Derya, Bateman, Lucinda, & Vernon, Suzanne D (2022). Improvement of Long COVID symptoms over one year.. Frontiers in medicine. https://doi.org/10.3389/fmed.2022.1065620
BibTeX
@article{mecfsatlas-oliveira-2022-improvement-long,
author = {Oliveira, Carlos R and Jason, Leonard A and Unutmaz, Derya and Bateman, Lucinda and Vernon, Suzanne D},
title = {Improvement of Long COVID symptoms over one year.},
journal = {Frontiers in medicine},
year = {2022},
doi = {10.3389/fmed.2022.1065620},
note = {PubMed: 36698810},
url = {https://www.mecfsatlas.com/evidence/oliveira-2022-improvement-long},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-30. https://www.mecfsatlas.com/evidence/oliveira-2022-improvement-long
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