[1] Wellcome Trust Ctr Human Genet, Oxford OX 37 BN, England
[2] Ernst Moritz Arndt Univ Greifswald, Dept Psychiat & Psychotherapy, Greifswald, Germany
[3] Univ Cologne, Dept Psychiat & Psychotherapy, Cologne, Germany
[4] Vestfoldklinikken, Dept Psychiat & Psychotherapy, Borgheim, Norway
[5] Univ Bonn, Dept Psychiat & Psychotherapy, D-5300 Bonn, Germany
[6] Univ Homburg, Dept Psychiat & Psychotherapy, D-6650 Homburg, Germany
[7] Univ Gottingen, Dept Psychiat & Psychotherapy, Gottingen, Germany
[8] Ernst Moritz Arndt Univ Greifswald, Inst Epidemiol & Social Med, Greifswald, Germany