PRO∗BPD: Effectiveness of outpatient treatment programs for borderline personality disorder: A comparison of Schema therapy and dialectical behavior therapy: Study protocol for a randomized trial 11 Medical and Health Sciences 1103 Clinical Sciences 11 Medical and Health Sciences 1117 Public Health and Health Services

Background: Borderline Personality Disorder (BPD) is a severe mental illness that is associated with low quality of life, low psychosocial functioning, and high societal costs. Treatments for BPD have improved in the last decades. Dialectical behavior therapy (DBT) and Schema therapy (ST) have demonstrated efficacy in reducing BPD symptoms and costs. However, research has not compared these two treatment approaches. In addition, there is a lack of 'real world studies' that replicate positive findings in regular mental healthcare settings. Thus, the PROgrams for Borderline Personality Disorder (PRO∗BPD) study will compare the (cost-) effectiveness of DBT and ST in structured outpatient treatment programs in the routine clinical setting of an outpatient clinic. Methods/Design: We aim to recruit 160 BPD patients, who will be randomly assigned to either DBT or ST. In both conditions, patients receive one group therapy and one individual therapy session/week for a maximum of 18 months. Both treatment programs have similar frameworks, which guarantee clinical equipoise. The primary outcome is a reduction of BPD-symptoms. Also, the costs related to BPD are assessed and an economic evaluation is performed from a societal perspective. Secondary outcomes examine other measures of BPD-typical and general psychopathology, comorbidity, quality of life, psychosocial functioning and participation. Data are collected prior to the beginning therapy and every six months until the end of therapy, as well as at six months, one year and two years of follow-up after the end of therapy. Finally, we conduct a qualitative study to understand patients' experiences with the two methods. Discussion: The PRO∗BPD study is the first randomized trial to compare the (cost-) effectiveness of DBT and ST. By examining the clinical effectiveness of a broad spectrum of outcome parameters, conducting an economic evaluation and assessing patients' experiences, this study will significantly advance our knowledge on psychotherapy for BPD and will provide insight into the treatment approaches that should be offered to different BPD patients from clinical, economic and stakeholder's perspectives. Trial registration: German Clinical Trial Register, DRKS00011534, Date of registration: 11/01/2017, retrospectively registered.