Objective To analyze the effectiveness of psychological treatments on symptom load and associated disability in children with functional somatic symptoms, and to explore potential moderators of effects.

Study design Cochrane, PubMed, PsycINFO, EMBASE, and CINAHL were searched for randomized controlled trials published in peer-reviewed journals. Randomized controlled trials studying the effect of a psychological treatment on symptom load and disability in children with functional somatic symptoms were selected. Data on symptom load, disability, and school absence directly post-treatment and at follow-up were extracted by 2 assessors. Studies were appraised with the Cochrane risk of bias tool. Standardized mean differences were pooled in a random-effects model. Heterogeneity in effect-sizes was explored by use of meta-regressions. PROSPERO Registration ID: CRD42015029667.

Results Out of 4098 identified records, 27 studies were included in this review of which 21 were included in meta-analyses. Psychological treatments reduced symptom load (Hedges g = −0.61), disability (Hedges g = −0.42), and school absence (Hedges g = −0.51) post-treatment in children suffering from various functional somatic symptoms. Effects were maintained at follow-up. Type and duration of symptoms, age, and treatment dose did not explain heterogeneity in effect-sizes between studies. Effect-sizes should be interpreted with caution because of the variety in outcome measures, unexplained heterogeneity in found effects and potential publication bias.