(36.8 %) or from recurrent depressive disorder (63.2 %). All included patients were of European descent and 88.7% were of German origin. 366 control subjects were matched to the patient sample for age, gender and ethnicity from a randomly selected Munich-based community sample and underwent a strict screening-procedure for the absence of psychiatric and severe somatic disease (Heck et al., 2009). The overall inclusion rate of all contacted probands was 50.3 %. These subjects thus represent a group of individuals from the general population who have never been mentally ill. Age, gender and ethnicity did not differ from the patient sample. This study has been approved by the ethics committee of the Ludwig-Maximilians-University (LMU) in Munich and written informed consent was obtained from all subjects.
