Combining Internet-delivered and face-to-face Cognitive Behavioral Therapy (CBT) for Somatic Symptom Disorder (iSOMA+): Effects of a blended psychotherapy

• Applicant: Dr. Severin Hennemann
• Subject Area: Personality Psychology, Clinical and Medical Psychology, Methodology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 543351897

Persistent somatic symptoms such as pain symptoms are common in the general population and lead to frequent medical consultations and high health care costs. Persistent somatic symptoms are often associated with dysfunctional cognitive, emotional or behavioral reactions and distress, which form the core feature of the somatic symptom disorder according to DSM-5. Psychological therapies, especially Cognitive Behavioral Therapy (CBT), can reduce somatic symptom severity and associated distress, but the clinical effects are comparatively low, the patient group is considered "difficult-to-treat" and the coverage rate of psychotherapy is low. The combination of on-site therapy sessions with internet- or app-based elements, so-called blended therapy represents an innovative approach that could increase the effectiveness of traditional psychotherapy as a "smart augmentation". The research field is still in its infancy and there is a lack of therapy studies on persistent somatic symptoms and somatic symptom disorder, respectively. The present trial therefore investigates a blended therapy in which a modular internet intervention ("iSOMA") is integrated into outpatient psychotherapy for patients with somatic symptom disorder. The two-arm randomized controlled trial will include 250 adult patients and will be treated at 8 sites (university psychotherapy centers). Patients will receive either the blended psychotherapy consisting of 20 sessions of CBT + iSOMA or a standard treatment (CBT + self-help book). The internet-based treatment (iSOMA) was developed by the applicants and consists of seven modules with psychoeducation, interactive exercises, homework and symptom monitoring. The modules will be integrated into the therapy process in a semi-structured way. The efficacy and acceptability of iSOMA as a stand-alone intervention for adults with persistent somatic symptoms have already been proven in a preliminary trial. For the current study, we expect that blended psychotherapy is superior to standard treatment in terms of reduction of somatic symptom severity (primary outcome) and secondary outcomes (e.g., improved symptom-coping, reduction of disability) at the end of therapy (primary outcome) and that these effects are stable until the 6-month follow-up. In order to find out who benefits from which treatment, mechanisms of the change process (e.g., self-efficacy, treatment agency) are examined.

• DFG Programme: Clinical Trials
• Co-Investigators: Professor Dr. Harald Baumeister; Professor Dr. Michael Witthöft