Patients are recruited across Berlin through psychiatric outpatient departments, the outpatient clinics of Charité, and social media. Recruitment occurs either through direct approach by psychologists or psychotherapists in training, or via informational posters and flyers. At baseline, eligibility screening is conducted by a blinded psychologist who is independent of the intervention delivery. This psychologist introduces the study, obtains electronic informed consent, and administers the self-report and clinician-rated assessments.
Given the behavioral nature of the interventions, participants and therapists are informed about group allocation after randomization. Randomization is performed using an Excel-generated list with block randomization (block size = 4).
Data management adheres to standard data protection procedures, including the use of anonymized identification codes and secure storage in an online database accessible only to authorized research team members. Participants retain the right to access their data and to request its deletion at any time. Upon completion of the study, each participant will receive compensation of 50 €.