Given that we had previously reported stronger evidence for association findings with the inclusion of bipolar samples, to the above meta-analysis, we added the UK bipolar dataset of the WTCCC(15). Data for additional bipolar samples from Iceland (n=404) and Norway (n=205) were also provided by the SGENE plus/GROUP consortia. To avoid the problem of shared controls, as before(4) the WTCCC bipolar data were combined with the UK schizophrenia cases before testing against the UK controls. Similarly, the Icelandic and Norwegian cases were combined with the respective schizophrenia cases from those countries.
