Background: Recurrent and impairing functional somatic syndromes (FSS) are common in adolescents. Despite a high need for care, empirically supported treatments are lacking for youth. The aim of this uncontrolled pilot study was to assess feasibility and treatment potential of a new intervention with group-based Acceptance and Commitment Therapy (ACT) in a generic treatment approach for adolescents with multiple FSS. Methods: Twenty-one patients received ‘ACT for Health in Adolescents’ (AHEAD) (30 h), specifically developed for adolescents (aged 15–19 years) with moderate to severe FSS. Close relatives attended an information meeting to facilitate support of the patients throughout treatment. Treatment satisfaction was evaluated by means of self-report and relatives’ impressions. Self-reported physical health at 3 months follow-up (FU) after end of treatment was the primary outcome whereas secondary outcomes included symptom burden, limitation due to symptoms, illness worry, emotional distress and physical and emotional symptoms. Treatment targets were assessed by measures on illness behaviour, illness perception and psychological inflexibility. Results: Nineteen patients (90.5%) completed the treatment with a high overall attendance rate of 93%. All would recommend the treatment to a friend with similar problems. Close relatives rated it valuable to participate in an information meeting. Patients’ physical health improved significantly from assessment to FU with a clinically relevant mean change of 8.9 points (95% CI [5.4; 12.4]; SRM 0.91 [0.26;1.57]). Improvement was also seen on all secondary outcome measures, from assessment to FU. Maladaptive illness behaviours and perceptions as well as psychological inflexibility showed a significant decline from assessment to FU. Conclusion: AHEAD was feasible and potentially efficacious and warrants testing in a larger clinical trial. Trial registration: Clinical Trials gov NCT04464447, registration date July 9th, 2020. Retrospectively registered.

Introduction Functional somatic syndromes (FSS) are common in adolescents, characterised by severe disability and reduced quality of life. Behavioural treatments such as acceptance and commitment therapy (ACT) has shown promising results in children and adolescents with FSS, but has focused on specific syndromes such as functional pain. The current study will compare the efficacy of group-based ACT with that of enhanced usual care (EUC) in adolescents with a range of FSS operationalised by the unifying construct of multiorgan bodily distress syndrome (BDS). Methods and analysis A total of 120 adolescents aged 15–19 and diagnosed with multiorgan BDS, of at least 12 months duration, will be assessed and randomised to either: (1) EUC: a manualised consultation with a child and adolescent psychiatrist and individualised treatment plan or (2) manualised ACT-based group therapy plus EUC. The ACT programme consists of 9 modules (ie, 27 hours) and 1 follow-up meeting (3 hours). The primary outcome is physical health, assessed by an Short Form Health Survey (SF-36) aggregate score 12 months after randomisation. Secondary outcomes include self-reported symptom severity, symptom interference, depression and anxiety, illness worry, perceived stress and global improvement; as well as objective physical activity and bodily stress response measured by heart rate variability, hair cortisol and inflammatory biomarkers. Process measures are illness perception, illness-related behaviour and psychological flexibility. Ethics and dissemination The study is conducted in accordance with Helsinki Declaration II. Approval has been obtained from the Science Ethics Committee of the Central Denmark Region and the Danish Data Protection. The results will be sought to be published according to the CONSORT statement in peer-reviewed journals. Discussion This is one of the first larger randomised clinical trials evaluating the effect of a group-based intervention for adolescents with a range of severe FSS. Trial registration number NCT02346071; Pre-results.

Unspecific somatic health complaints and symptoms are common in children and adolescents, varying on a continuum of severity. When persistent and impairing, they are often referred to as functional somatic syndromes (FSS). The overarching objective of this paper is to provide an overview of the pediatric literature in relation to conceptual, assessment, and treatment issues for youth presenting with FSS. Clinical recommendations are outlined including addressing potential feasibility and barrier issues for families presenting to medical and mental health services. Assessment and treatment issues are further discussed in context of two recent psychotherapy trials conducted with children and older age adolescents (aged from 7 to 19 years). Finally, we address ongoing research gaps in this field with view to strengthen the evidence base in the assessment and treatment of youth presenting with FSS.

Background: Evidence for treatment of adolescents with multiple functional somatic syndromes (FSS) is sparse. This study examined the efficacy of ‘Acceptance and Commitment Therapy for Health in Adolescents’ (AHEAD), a generic group‐based treatment for adolescents with co‐occurrence of multiple FSS.Methods: A randomized trial was conducted at a specialized university hospital clinic. Adolescents (15–19 years) with multiple FSS of at least 1 year's duration were randomly assigned to AHEAD or enhanced usual care (EUC). AHEAD consisted of nine modules (i.e., 27 h) and one follow‐up meeting. Primary outcome was physical health (SF‐36). Various secondary outcomes and treatment targets were included (e.g., symptom severity, symptom impact, and illness perception). A linear mixed‐effects model was used for analysis. Trial‐registration: ClinicalTrials.gov NCT02346071.Results: Ninety‐one patients were included. At 12 months, no significant difference in physical health was identified between groups (mean adjusted difference 1.2 [95% CI −1.6 to 4.0], p = .404). However, different developments over time were seen with an interaction effect between intervention arm and time (χ²(5) = 14.1, p = .0148). AHEAD patients (n = 44) reported a clinically relevant improvement at end of treatment and at 8 and 12 months, while EUC patients (n = 47) displayed a clinically relevant improvement at 12 months. Furthermore, AHEAD patients showed a faster improvement on symptom severity, symptom impact and illness perception. EUC patients received more psychological treatment outside the trial (p ≤ .001) than AHEAD patients. Treatment satisfaction with AHEAD was high in contrast to EUC.Conclusions: Compared with EUC, AHEAD had no additional advantage on the improvement of physical health at the primary endpoint of 12 months. However, a faster improvement of physical health was seen in AHEAD and considerably more psychological treatment was received outside the trial in EUC with clinically meaningful improvements in both groups. The results underpin the importance of an organised and systematic treatment offer for the most severely affected youth.