Evaluating working memory functioning in individuals with myalgic encephalomyelitis/chronic fatigue syndrome: a systematic review and meta-analysis. — CFSMEATLAS
Evaluating working memory functioning in individuals with myalgic encephalomyelitis/chronic fatigue syndrome: a systematic review and meta-analysis.
Penson, Maddison, Kelly, Kate · Psychology, health & medicine · 2026 · DOI
Quick Summary
This study reviewed 34 research papers to understand how ME/CFS affects working memory—the ability to hold and use information in your mind briefly. The researchers found that people with ME/CFS have significant difficulties with verbal working memory (remembering words and language), but their ability to remember visual information (like images or patterns) appeared similar to people without ME/CFS. This suggests that cognitive problems in ME/CFS may affect certain types of thinking more than others.
Why It Matters
Understanding which specific cognitive abilities are affected in ME/CFS is essential for validating patient experiences of 'brain fog' and cognitive impairment, which are often underrecognised in clinical settings. These findings can guide targeted cognitive interventions and help clinicians recognise and appropriately support cognitive manifestations as a core feature of ME/CFS rather than a secondary symptom.
Observed Findings
Large effect size demonstrating significant impairment in verbal working memory performance in ME/CFS cohorts compared to healthy controls
No significant difference in visual working memory performance between ME/CFS and control groups
Consistent verbal working memory deficits across both span/attentional control tasks and broader verbal domains
Good to strong methodological quality of included studies
34 studies met inclusion criteria across six major databases after systematic screening of 10,574 papers
Inferred Conclusions
Cognitive impairment in ME/CFS shows domain-specific rather than global working memory dysfunction, with verbal systems disproportionately affected
Higher-order verbal cognitive processes may be more vulnerable than visual-spatial processing in ME/CFS
Cognitive manifestations warrant recognition and integration into clinical care pathways for ME/CFS
Future research should focus on understanding mechanisms underlying verbal working memory deficits and their relationship to disease severity and other symptoms
Remaining Questions
What are the neurobiological mechanisms underlying the selective impairment of verbal versus visual working memory in ME/CFS?
What This Study Does Not Prove
This study does not establish the underlying biological mechanisms causing verbal working memory deficits in ME/CFS, nor does it prove that verbal cognitive impairment is present in every individual with ME/CFS. The meta-analysis synthesises group-level patterns and cannot determine whether observed deficits are permanent, reversible, or fluctuate with illness severity.