Design
RECRUITMENT
This single-arm feasibility study was conducted between September 2016 and December 2021 at outpatient departments in Heidelberg (Institute for Psychosocial Prevention of the University Hospital Heidelberg, Centre for Psychosomatic Medicine) and Mainz (Rheinhessen Fachklinik, Department of Child and Adolescent Psychiatry and Psychotherapy of the University Medical Centre Johannes Gutenberg University Mainz), Germany. The study design and procedure are outlined in detail in the study protocol [The study first started as an RCT to investigate the effectiveness of MBT-CD compared to treatment as usual (TAU) and was changed in consent with the funders into a single-arm feasibility and pilot study due to recruitment and randomization difficulties in the first two years of the study. The design of the feasibility study was adaptive, i.e., changes in intervention and scientific assessments were made over the course of the study to improve treatment and study retention on the basis of patient experience.