1 Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University of Duisburg-Essen, Essen, Germany.
2 Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University of Duisburg-Essen, Essen, Germany. anke.hinney@uk-essen.de.
3 Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University of Duisburg-Essen, Essen, Germany. Jochen.Antel@uni-due.de.