ME Association regular research roundup

ME/CFS and Long Covid Research: 18 – 24 April 2023

The weekly research round-up includes recent publications about ME/CFS and Long Covid. We highlight the studies that have particularly caught our interest and follow these with the full list of publications together with their abstracts (summaries).

There have been four new ME/CFS studies and twelve new Long Covid studies this week.


The ME Association maintains a comprehensive index of published research on ME/CFS and Long Covid that is free to use and updated weekly.

Audio Commentary by Dr Katrina Pears

There has been a number of similar studies this week, which detail the prevalence and demographics of ME/CFS in the population, further showing the extent of disease severity. There were no biomedical studies this week. As there was no one study which we could focus an extended review of this week, we have highlighted some of the key points from three studies:

Paper two (2) looks at the socio-economic determinants of ME/CFS in Norway, finding that high educational attainment is associated with a 19% increased risk in developing ME/CFS and high household income is associated with a 18% increase in risk of developing ME/CFS. Whereas, low educational attainment is associated with a 69% decrease in the risk of developing ME/CFS and a low household income is associated with 53% increase.

This is a thought-provoking large study showing that socioeconomic status (SES) is a strong predictor for the risk of developing ME/CFS, and brings up many questions over the real prevalence of ME/CFS and the effects of mis or non-diagnosis with differing socioeconomic status.

Paper three (3) looks at ME/CFS in a Swiss population and characterises the population through questionnaires and interviews. The results from this research found the majority of patients to be female (72.2%), single (55.7%) and without children (62.5%), with only one third working (full or part-time). Furthermore, the mean onset of ME/CFS was 31.6 years of age with 15% of patients being symptomatic before their 18th birthday. Interestingly, 90% of the participants could recall the triggering event and times of onset and infectious disease was associated with the vast majority, with Epstein Barr Virus (EBV) being commonly reported. Patients in this study reported 13 different symptoms, and 82.2% suffered from co-morbidities.

This study gives some good data to show the prevalence within the Swiss population, although compared to the other studies reported this week it is on a much smaller scale with 172 participants. Intriguingly, the study observed a high number of participants from the medical profession, such as nurses.

In addition this week paper four (4) reports on the initial findings from the questionnaires received for the DecodeME study. This is a preprint, meaning the science has not been peer-reviewed and verified. DecodeME is the world’s largest study on ME/CFS aiming to uncover the genetics behind the illness.

The study provides a plain English summary which details the main findings from analysing the responses to 17,074 questionnaires, these are questionnaires which are completed on initial sign-up to the study. Findings so far have found important subgroups in ME/CFS, which will help in future analysis of the illness. Interestingly, not only is there a higher prevalence in the female population but females tend to have more symptoms and more co-occurring conditions. Furthermore, what hasn't been discovered before, is that being female, older, and having the illness for over 10 years is associated with greater severity of symptoms.

It is truly impressive to see results from the study which is still in its infancy and still recruiting. DecodeME has already provided some fascinating findings some of which are expected, others not, and it is worth a look at Figure 3 in the paper, which shows some of the key findings, such as duration of illness, severity and infection triggers.

It is noteworthy this week to see a number of very similar studies, which together all report comparable results over three different countries, all showing high disease burden and high prevalence in the female population. These studies show the subgroups in ME/CFS, which could help to advance research if participants are separated, instead of grouping the whole illness together. I hope that studies like these will help to demonstrate the need for improvement in knowledge and acceptance in healthcare, and lead to advances in research.

ME/CFS Research References and Abstracts 

1. Associations between daily routines and social support among women with chronic fatigue syndrome

Morit Rosenberg, Tami Bar-Shalita, Miryam Weiss, Galia Rahav & Michal Avrech Bar.

Scandinavian Journal of Occupational Therapy.


Background: Chronic fatigue syndrome (CFS) is characterised by extreme fatigue, as well as physical and cognitive symptoms. CFS is thrice as prevalent in women than in men.

Objective: To compare women with and without CFS concerning social support and participation in daily routine occupations, and to assess the relationships between the two variables among women with CFS.

Methods: This study included 110 women aged 24–69: 41 were diagnosed with CFS and 64 were not diagnosed with CFS. Participants completed the Occupational Questionnaire and the Medical Outcomes Study (MOS) Social Support Survey.

Results: Women with CFS reported lower participation in instrumental activities of daily living and work occupations than women without CFS. However, they spend more time resting and enjoying it. In addition, they reported less social support than women without CFS. Positive correlations were found between the number of close friends and time spent in play and leisure occupations and a negative correlation with sleep/rest.

Conclusions: Women with CFS participate less in IADL and work occupations and more in rest/sleep than women without CFS and their social support is attenuated.

2. Socioeconomic determinants of myalgic encephalomyelitis/chronic fatigue syndrome in Norway: a registry study

Geir Haakon Hilland, Kjartan Sarheim Anthun.

ResearchSqaure [Preprint]


Background: Previous research has shown that socioeconomic status (SES) is a strong predictor of chronic disease. However, to the best of our knowledge, there has been no studies of how SES affects the risk of Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) that has not been based upon self-reporting or retrospectively screening of symptoms.

As far as we know, this is therefore the first study that isolate and describe socioeconomic determinants of ME/CFS and calculate how these factors relate to the risk of ME/CFS diagnosis by utilizing individual level registry data, which allows for objective operationalization of the ME/CFS population, and the utilization of different control groups.

Data and methods: We utilize health registry data from all adult patients diagnosed with ME/CFS from 2016-2018 in Norway, coupled with socioeconomic data from statistics Norway from 2009-2018. We operationalize SES as household income and educational attainment fixed at the beginning of the study period. We compare the effects of SES on the risk of ME/CFS diagnosis to a population of patients with hospital diagnoses that share clinical characteristics of ME/CFS and a healthy random sample of the Norwegian population. Our models are estimated by logistic regression analyses.

Results: When comparing the risk of ME/CFS diagnosis with a population consisting of people with four specific chronic diseases, we find that high educational attainment is associated with a 19% increase (OR: 1.19) in the risk of ME/CFS and that high household income is associated with a 18% increase (OR:0.82) in risk of ME/CFS. In model 2, when comparing with a healthy population sample, we find that low educational attainment is associated with 69% decrease (OR:0.31) in the risk of ME/CFS and that low household income is associated with a 53% increase (OR: 1.53).

Conclusion: We find statistically significant associations between SES and the risk of ME/CFS. However, our more detailed analyses shows that our findings vary according to which population we compare the ME/CFS patients with, and that the effect of SES is larger when comparing with a healthy population sample, as opposed to controls with selected hospital diagnoses.

3. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): A preliminary survey among patients in Switzerland

Rea Tschopp; Rahel S. König; Protazy Rejmer; Daniel H. Paris.

Heliyon, Volume 9, Issue 5, e15595, May 2023.


Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a multi-factorial systemic chronic debilitating disease of poorly understood etiology and limited systematic evidence.

The questionnaire and interview-based survey included 169 ME/CFS patients from the Swiss ME/CFS association. The majority of patients were females (72.2%), single (55.7%) and without children (62.5%). Only one third were working (full/part-time). The mean onset of ME/CFS was 31.6 years of age with 15% of patients being symptomatic before their 18th birthday.

In this cohort, patients had documented ME/CFS for a mean 13.7 years, whereby half (50.3%) stated their condition was progressively worsening. Triggering events and times of disease onset were recalled by 90% of the participants. An infectious disease was associated with a singular or part of multiple events by 72.9% and 80.6%, respectively.

Prior to disease onset, a third of the patients reported respiratory infections; followed by gastro-intestinal infections (15.4%) and tick-borne diseases (16.2%). Viral infections were recalled by 77.8% of the respondents, with Epstein Barr Virus being the most commonly reported agent.

Patients self-reported an average number of 13 different symptoms, all described specific triggers of symptoms exacerbation and 82.2% suffered from co-morbidities.

This study collated clinically relevant information on ME/CFS patients in Switzerland, highlighting the extent of disease severity, the associated factors negatively affecting daily life activities and work status as well as potential socio-economic impact.

4. Typing myalgic encephalomyelitis by infection at onset: A DecodeME study

Andrew D. Bretherick; Simon J. McGrath; Andy Devereux-Cooke; Sian Leary; Emma Northwood; Anna Redshaw; Pippa Stacey; Claire Tripp; Jim Wilson; Sonya Chowdhury; Isabel Lewis; Øyvind Almelid; Sumy V. Baby; Tom Baker; Hannes Becher; Thibaud Boutin; Malgorzata Clyde;, Diana Garcia; John Ireland; Shona M. Kerr; Ewan McDowall; David Perry; Gemma L. Samms; Veronique Vitart; Jareth C. Wolfe; Chris P. Ponting.

NIHR Open Research [Preprint]


Background: People with myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) daily experience core symptoms of post-exertional malaise, unrefreshing sleep, and cognitive impairment or brain fog. Despite numbering 0.2-0.4% of the population, no laboratory test is available for their diagnosis, no effective therapy exists for their treatment, and no scientific breakthrough regarding their pathogenesis has been made. It remains unknown, despite decades of small-scale studies, whether individuals experience different types of ME/CFS separated by onset-type, sex or age.

Methods: DecodeME is a large population-based study of ME/CFS that recruited 17,074 participants in the first 3 months following full launch. Their detailed questionnaire responses provided an unparalleled opportunity to investigate illness severity, onset, course and duration.

Results: The well-established sex-bias among ME/CFS patients is evident in the initial DecodeME cohort: 83.5% of participants were females. What was not known previously was that females’ comorbidities and symptoms tend to be more numerous than males’. Moreover, being female, being older and being over 10 years from ME/CFS onset are significantly associated with greater severity.  Five different ME/CFS onset types were examined in the self-reported data: those with ME/CFS onset (i) after glandular fever (infectious mononucleosis); (ii) after COVID-19 infection; (iii) after other infections; (iv) without an identified infectious onset; and, (v) where the occurrence of an infection at or preceding onset is not known.

Conclusions: This revealed that people with a ME/CFS diagnosis are not a homogeneous group, as clear differences exist in symptomatology and comorbidity.

Long-COVID Research References

  1. Increased interleukin-6 is associated with long COVID-19: a systematic review and meta-analysis
  2. Fifteen-minute consultation: Managing post-COVID-19 syndrome (long COVID) in children and young people
  3. Cardiovascular Manifestations of the Long COVID Syndrome
  4. Autonomic Dysfunction related to Post-Acute SARS-CoV-2 Syndrome
  5. Effect of Post-COVID-19 on Brain Volume and Glucose Metabolism: Influence of Time Since Infection and Fatigue Status
  6. Chronic Disease Self-Management of Post-Acute Sequelae of COVID-19 Among Older Adults: A Mixed-Methods Analysis
  7. Persistent post-COVID-19 dysosmia: Practices survey of members of the French National Union of Otorhinolaryngology-Head and Neck Surgery Specialists. CROSS analysis
  8. Transcranial direct current stimulation for post-COVID fatigue: a randomized, double-blind, controlled pilot study
  9. Exaggerated blood pressure elevation in response to orthostatic challenge, a post-acute sequelae of SARS-CoV-2 infection (PASC) after hospitalization
  10. Long COVID and especially headache syndromes
  11. Lung perfusion assessment in children with long-COVID: A pilot study
  12. Long COVID: Where Are We in 2023?

Dr Katrina Pears,
Research Correspondent.
The ME Association.

Dr Katrina Pears - MEA Research Correspondent
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