Abstract
BACKGROUND: Functional abdominal pain disorders (FAPDs) are disorders of the gut-brain interaction. FAPDs are common in children and adolescents (global prevalence 12%) and are associated with psychiatric comorbidity. Internet-delivered cognitive-behavioral therapy (iCBT) is effective for FAPDs, but it's unclear whether children with psychiatric comorbidities benefit equally from the treatment. OBJECTIVES: In this study, we assessed whether having a comorbid psychiatric diagnosis results in different rates of change in iCBT for children with FAPDs. DESIGN: Between-groups design. METHODS: Participants were 120 children with FAPDs (age 8-12 years) taking part in one of two clinical trials testing 10 weeks of iCBT. For the analyses, participants were divided into groups: presence or absence of psychiatric disorder. The primary outcome was gastrointestinal symptoms, assessed weekly using the Pediatric Quality of Life Gastrointestinal Symptom Scale. Secondary outcomes included health-related quality of life, gastrointestinal-specific anxiety, and pain intensity. Multilevel modeling was used to assess differences in rates of change between groups from baseline to follow-up directly after treatment, and then to 6-month follow-up. RESULTS: We observed significant improvements in the rates of change for both groups for the primary outcome (gastrointestinal symptoms) and all secondary outcomes during treatment. Children with psychiatric comorbidity had significantly more severe symptoms at baseline on all measures, but there was no difference in the rates of change for the primary outcome (-0.29, 95% confidence interval (CI): -0.70, 0.11, p = 0.159) or any of the secondary outcomes compared to the non-comorbid group. Treatment benefits were sustained at 6-month follow-up. CONCLUSION: ICBT seems to be beneficial for children with FAPDs, also in the presence of psychiatric comorbidity. Given the high prevalence of psychiatric comorbidity in this patient group, the results will aid the clinical assessment and treatment planning for these patients.