Cognitive behavioural therapy A transdiagnostic intervention for severe fatigue with a focus on post-COVID-19 fatigue

Post-COVID-19 related fatigue (PCRF) is a prevalent symptom with a substantial impact on daily functioning. Due to the magnitude of the pandemic PCRF has considerable impact on society.
Part 1 of this thesis presents research on cognitive behavioural therapy (CBT) for severe PCRF. A multicentre 2-arm randomised controlled trial showed that adult patients who received CBT reported less severe fatigue, concentration problems and physical complaints, and improved physical and social functioning compared to patients in the control condition directly following treatment. Favourable outcomes were maintained at follow-up, 1 year following CBT. The reduction in fatigue was associated with changes in perceptions and beliefs about fatigue. A pilot study suggested that CBT for post-COVID-19 fatigue is also effective for adolescents.
Part 2 addresses variations in the response to CBT for severe fatigue in patients with chronic fatigue syndrome (ME/CFS). Younger patients, patients who were more active and patients with less functional impairment benefitted more from CBT. Patients with comorbid depressive symptoms benefited less from internet-based CBT than patients without and can better be offered face-to-face CBT. Co-occurence of severe fatigue and insomnia did not affect treatment outcomes.
Part focuses on CBT as a transdiagnostic intervention for fatigue. Comparison of patients with PCRF, with patients with ME/CFS and Q-fever fatigue syndrome showed that diagnoses had only limited value in explaining variance in fatigue severity, putative fatigue maintaining factors and response to CBT. These findings support the idea that PCRF, and its treatment, fits into a transdiagnostic cognitive behavioural approach of fatigue.