1. Department of Psychiatry and Psychotherapy , University Medical Center of the Johannes Gutenberg-University Mainz , Untere Zahlbacher Str. 8, D-55131 Mainz , Germany
2. Department of Human Biology and Human Genetics , University of Kaiserslautern , Erwin-Schrödinger-Straße 13, D-67663 Kaiserslautern , Germany