We calculated BP polygenic risk scores in our SCZ sample using our full, independent BP dataset. All factor scores were split at the median into two equally sized sets. For all factor scores, now dichotomized, we asked whether polygenic score of BP risk predicted whether SCZ subjects were above or below the median on the symptom factor using logistic regression with sample and MDS as covariates. Risk scores were calculated for 10 p-value thresholds from 0.001 to 1 for each symptom dimension. Polygenic score of BP was associated only with the manic factor in SCZ subjects, with a p-value threshold of 0.3 having significance p=0.003 and pseudo variance explained of ~2% (Figure 4, Supplementary Table 5). Applying the same test to the quantitative mania score yields, a more significant result (p=2.51×10−5). We tested each individual schizophrenia sample independently to ensure no single sample was solely driving the finding. Mania score distributions differed by sample; however, significance was seen across multiple samples and removal of any single sample did not appreciably change the overall result (Supplementary Table 6). The correlation between
