Title {1}	Understanding and breaking the intergenerational cycle of abuse in families enrolled in routine mental health and welfare services: study protocol for a randomized controlled trial and non-interventional trials investigating mechanisms of change within the UBICA II consortium
Trial registration {2a and 2b}.	Registry: German Clinical Trials Register Trial Identifier: DRKS00017398
Protocol version {3}	Study Protocol Version 1.6, 26.04.2021
Funding {4}	This study is funded by the German Federal Ministry of Education and Research (Funding number: 01KR1803B, 01KR1803C). The Federal Ministry of Education and Research was neither involved in the design of the study nor in collection, analysis, and interpretation of data or in writing the manuscript.
Author details {5a}	CN: Department of General Psychiatry, Center for Psychosocial Medicine, Heidelberg University, Heidelberg, Germany. FB: Department of Psychiatry and Psychotherapy, Berlin Institute of Health, Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, Campus Charité Mitte, Berlin, Germany, Berlin, Germany. MK: Department of Child and Adolescent Psychiatry, Center for Psychosocial Medicine, Heidelberg University, Heidelberg, Germany and University Hospital of Child and Adolescent Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland. ST: Department of Psychosocial Prevention, University Hospital of Heidelberg, Heidelberg, Germany. KB: Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Campus Virchow-Klinikum, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Berlin, Germany. AD: Institute of Medical Informatics and Statistics, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany. SCH: Department of General Psychiatry, Center for Psychosocial Medicine, Heidelberg University, Heidelberg, Germany.
Name and contact information for the trial sponsor {5b}	Heidelberg University Hospital, Im Neuenheimer Feld 325, 69120 Heidelberg, Germany
Role of sponsor {5c}	The sponsor and funders do not have any authority over research activities.