Neuropsychological dysfunction in chronic fatigue syndrome and the relation between objective and subjective findings.
Rasouli, Omid, Gotaas, Merethe Eide, Stensdotter, Ann-Katrin et al. · Neuropsychology · 2019 · DOI
Quick Summary
This study tested whether people with ME/CFS who report having trouble thinking and remembering actually show problems on objective cognitive tests. Researchers gave 236 patients questionnaires about memory difficulties and gave them various thinking tests. They found that patients' own reports of cognitive problems didn't strongly match their actual test results, but those with higher fatigue, pain, and depression tended to report more thinking difficulties. The actual cognitive problems found on testing were mainly in speed of thinking and attention.
Why It Matters
Understanding the gap between subjective cognitive complaints and objective test results is crucial for ME/CFS patients, as it clarifies that 'brain fog' reports may reflect mood and pain rather than measurable cognitive deficits alone. This finding helps researchers and clinicians better interpret patient complaints and informs whether cognitive interventions should target actual cognitive impairment or the emotional and physical factors driving symptom perception.
Observed Findings
Weak correlations (p < .05 but not p < .001) emerged between subjective cognitive complaints (EMQ) and objective measures of attention, verbal learning/memory, and working memory.
Subjective cognitive complaints were strongly associated with fatigue, pain, and depression (p < .001).
Between 21% and 38% of ME/CFS patients performed below the clinical impairment cutoff (1.5 SD below normal) on Stroop tests measuring attention and psychomotor speed.
Pain was negatively associated with objective working memory performance (p < .001) on the PASAT.
Self-reported cognitive performance did not show strong correlations with objective cognitive performance across any cognitive domain tested.
Inferred Conclusions
In ME/CFS, self-reported cognitive difficulties may be driven more by fatigue, pain, and mood disturbance than by underlying objective cognitive impairment.
Objective cognitive deficits in ME/CFS patients are primarily evident in domains of psychomotor speed and attention, not necessarily in all areas patients report difficulty with.
Clinicians should not assume patient reports of cognitive problems directly reflect measurable cognitive dysfunction; assessment of mood, pain, and fatigue is essential for understanding cognitive complaints.
Remaining Questions
Why do patient perceptions of cognitive problems not align with objective test results, and what mechanisms link fatigue, pain, and depression to subjective cognitive complaints?
What This Study Does Not Prove
This study does not prove that subjective cognitive complaints are purely psychological or invalid—it only shows weak correlation with these specific tests. Cross-sectional design prevents any causal claims about the relationship between fatigue, pain, depression, and cognitive difficulties. The study does not establish whether the observed cognitive deficits worsen over time or resolve with treatment.
Tags
Symptom:Cognitive DysfunctionPainFatigue
Method Flag:PEM Not DefinedWeak Case DefinitionNo Controls
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 →