All patients were male and of self reported German ancestry. All fulfilled DSM-IV criteria for AD and had been recruited from consecutive admissions to the psychiatry- and addiction medicine departments of German psychiatric hospitals participating in the German addiction research network (for a detailed description see Treutlein et al. 2009). The 900 additional patients included in GWAS2 were drawn from the 1,024 patients used to follow-up the 140 top SNPs from GWAS1 in our previous study (mean age at interview=43.3. SD=8.4 (GWAS2), mean=41.9. SD=8.8 (overall sample); mean age at onset =30.2, SD=7.8 (GWAS2) mean=27.0, SD=8.0 (overall sample).
