Co-occurrence of severe fatigue and insomnia: implications for the outcome of cognitive behavioural therapies.
Rauwerda, Nynke L, Kuut, Tanja A, Braamse, Annemarie M J et al. · Behavioural and cognitive psychotherapy · 2025 · DOI
Quick Summary
This study looked at whether having both severe fatigue and sleep problems at the same time affects how well cognitive behavioural therapy (CBT) works. Researchers found that CBT was equally effective whether patients had just fatigue, just insomnia, or both together. Interestingly, when one symptom improved during treatment, the other often improved too—but sometimes one symptom stayed even after the other got better.
Why It Matters
Many ME/CFS patients experience both severe fatigue and sleep disturbances simultaneously, yet evidence on how to treat these co-occurring symptoms has been limited. This study shows that standard CBT approaches remain effective despite symptom co-occurrence, providing reassurance to patients considering these therapies. The finding that symptoms can improve together suggests shared underlying mechanisms that warrant further investigation.
Observed Findings
CBT-F and CBT-I showed similar effectiveness regardless of whether patients had co-occurring symptoms (no significant differences between groups)
Changes in fatigue and insomnia severity were positively correlated during both treatments (r=0.30 for CBT-F, r=0.50 for CBT-I)
31% of ME/CFS patients who no longer met criteria for severe fatigue after CBT-F still reported clinical insomnia
24% of insomnia patients without clinical insomnia after CBT-I remained severely fatigued
Treatment outcomes showed small effect sizes, suggesting the co-occurring symptom did not substantially impair response to targeted therapy
Inferred Conclusions
CBT-F and CBT-I maintain their efficacy when severe fatigue and insomnia co-occur, supporting their use in this population
Changes in fatigue and insomnia severity are associated, suggesting potential shared pathophysiological mechanisms
Successful treatment of the primary symptom does not guarantee resolution of the co-occurring symptom, indicating independent maintenance mechanisms
Remaining Questions
What mechanisms explain the association between fatigue and insomnia improvements—are they causally related, or do they share common underlying pathology?
What This Study Does Not Prove
This observational study cannot establish causation between fatigue and insomnia improvements—the association may reflect shared biological pathways, placebo effects, or unmeasured confounders. The study does not prove that CBT is the optimal treatment for all patients with both conditions, nor does it explain why some patients experience residual symptoms despite successful primary treatment. The findings may not generalize beyond the studied populations or treatment protocols.
Why do approximately 25-31% of patients continue experiencing the co-occurring symptom despite successful primary treatment—what patient or symptom characteristics predict persistent residual symptoms?
Would combined or integrated CBT approaches (addressing both fatigue and insomnia simultaneously) achieve better outcomes than sequential or single-target treatments?
How do these findings apply to ME/CFS specifically, given the heterogeneous nature of the fatigue and the complex relationship between post-exertional malaise and sleep disturbances?