E2 ModerateModerate confidencePEM not requiredCross-SectionalPeer-reviewedReviewed
Psychomotor functioning in chronic fatigue syndrome and major depressive disorder: a comparative study.
Schrijvers, D, Van Den Eede, F, Maas, Y et al. · Journal of affective disorders · 2009 · DOI
Quick Summary
This study compared how quickly people with ME/CFS and depression could complete two drawing tasks—one simple and one complex. Both patient groups worked more slowly than healthy people, but the pattern of slowness differed between the two conditions. People with depression were especially slow at simple motor tasks, while both patient groups struggled similarly with the more cognitively demanding task.
Why It Matters
ME/CFS and depression share overlapping symptoms, making clinical differentiation challenging. This study directly examines psychomotor performance patterns to clarify how the two conditions differ mechanistically, which could improve diagnostic accuracy and inform treatment strategies tailored to each disorder's specific motor and cognitive deficits.
Observed Findings
- Both CFS and MDD patients showed slower overall performance compared to healthy controls on computerized copying tasks.
- MDD patients required significantly more time than CFS patients for simple line-copying (primarily motor task).
- No significant between-group performance difference emerged for complex figure-copying (cognitively demanding task).
- Both patient groups showed similar increases in reaction time as task complexity increased, with effect sizes comparable between CFS and MDD groups.
- All participants were female; most were taking psychotropic medications.
Inferred Conclusions
- Fine motor functioning is preferentially impaired in MDD compared to CFS.
- CFS and MDD show similar patterns of cognitive slowing despite differing motor profiles.
- The motor component of psychomotor slowing is more pronounced in MDD, while cognitive components are similarly affected in both disorders.
Remaining Questions
- Do these psychomotor differences persist in male patients with ME/CFS and depression, or are they sex-specific?
- What is the contribution of psychotropic medication to observed motor and cognitive slowing in both groups?
What This Study Does Not Prove
This cross-sectional study cannot establish causality or explain why these motor differences exist at a neurobiological level. The all-female sample and widespread psychotropic medication use limit generalizability, and the study does not clarify whether psychomotor slowing in CFS is a primary disease feature or secondary to other ME/CFS pathophysiology.
Tags
Symptom:Cognitive DysfunctionFatigue
Method Flag:PEM Not DefinedWeak Case DefinitionSmall SampleSex-StratifiedMixed Cohort
Metadata
- DOI
- 10.1016/j.jad.2008.08.010
- PMID
- 18817977
- Review status
- Editor reviewed
- Evidence level
- Single-study or moderate support from human research
- Last updated
- 12 April 2026
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 →
Contribute
Private, reviewed by a human. Not a public comment thread.