[1] Univ Med Ctr Hamburg Eppendorf, Dept Psychiat & Psychotherapy, Ctr Interdisciplinary Addict Res, Martinistr 52, D-20246 Hamburg, Germany
[2] Univ Med Ctr Hamburg Eppendorf, Inst Med Biometry & Epidemiol, Hamburg, Germany
[3] Ev Klinikum Bielefeld, Dept Psychiat & Psychotherapy Bethel, Bielefeld, Germany
[4] Paracelsus Univ Nuremberg, Dept Psychiat & Psychotherapy, Nurnberg, Germany
[5] Hannover Med Sch, Dept Psychiat Socialpsychiat & Psychotherapy, Hannover, Germany
[6] Lehrkrankenhaus Univ Duisburg Essen, Dept Psychiat Psychotherapy & Addict Med, Essen, Germany
[7] Univ Duisburg Essen, Dept Psychiat & Psychotherapy, LVR Klin Essen, Essen, Germany
[8] LVR Klin Cologne, Dept Addict Disorders & Psychiat, Cologne, Germany