Forest plots for genome-wide significant SNPs showed the same direction of effect for most or all of the five disorders (figure 2). For three of the four associated regions, the meta-analysis heterogeneity p value was not significant and a model in which all five disorders contributed provided the best fit (table 1). The exception was rs1024582, for which the heterogeneity p value was significant and the best-fit model supported an effect limited to bipolar disorder and schizophrenia (table 1). Appendix pp 38–45 shows the profile of the Bayesian and Akaike information criteria measures for each SNP for a range of models. We examined the association between the five disorders of four SNPs showing genome-wide significant association with bipolar disorder (table 2) and ten associated with schizophrenia (table 2).6,7 Appendix pp 46–61 show forest plots and model-fitting results by disorder. The best-fitting model for seven of the 14 risk SNPs suggested disorder-specific effects for either bipolar disorder (three SNPs) or schizophrenia (four SNPs), whereas the rest were consistent with more pleiotropic models (table 2).
