The Effect of Internet-Based Cognitive Behavioral Therapy (I-CBT) for Severe Fatigue in Adolescents with Immune Dysregulation Disorders: Preliminary Findings using a Multiple Single-Case Experimental Design

Publication date

2026-03

Authors

Nijhof, Linde
Vroegindeweij, AnoukORCID 0000-0002-7769-5459
Houtveen, Jan
Knoop, Hans
van Montfrans, JMISNI 0000000387128439
Onghena, Patrick
van de Putte, Elise M.ISNI 0000000388425371
Nijhof, Sanne L.ORCID 0000-0003-1538-5014ISNI 0000000419446029

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Document Type

Article

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Abstract

Severe fatigue in adolescents with immune dysregulation disorders (IDD) is prevalent and affects daily functioning. This study tested Internet-based cognitive behavior therapy (I-CBT) for the treatment of persistent fatigue in adolescents with IDD. This study used a multiple single-case experimental design (SCED) with a randomized waiting list period of 7-26 weeks, followed by 26 weeks of I-CBT and a 16-week follow-up. Nine adolescents participated, focusing on fatigue severity as the primary outcome. Secondary outcomes included physical functioning, school absence, and, if applicable, pain severity. Pre-post-differences were examined across subjects and individually for weekly measures. At the group level, pre-post-differences in primary and secondary outcomes were examined using mixed models. The across-subject analyses demonstrated the expected effect for fatigue severity. Furthermore, there was a significant reduction in fatigue severity and school absence, and improvement in physical functioning. Single-case analyses demonstrated significant reductions in fatigue in 5/9 patients post-I-CBT, with improvements in physical functioning noted in 6/9 patients. Effect sizes ranged from medium to large. Pain severity significantly improved in 1/5 patients with a small effect size. In a sample of nine adolescents, results indicated that I-CBT could be an effective and feasible treatment of persistent severe fatigue in IDD.

Keywords

Adolescent, Cognitive behavioral therapy, Fatigue, Immune dysregulation disorder, Pediatric rheumatic diseases, Clinical Psychology

Citation

Nijhof, L N, Vroegindeweij, A, Houtveen, J, Knoop, H, van Montfrans, J M, Onghena, P, van de Putte, E M & Nijhof, S L 2026, 'The Effect of Internet-Based Cognitive Behavioral Therapy (I-CBT) for Severe Fatigue in Adolescents with Immune Dysregulation Disorders : Preliminary Findings using a Multiple Single-Case Experimental Design', Journal of clinical psychology in medical settings, vol. 33, no. 1, pp. 119-129. https://doi.org/10.1007/s10880-025-10096-y