but not to several non-psychiatric diseases (which suggested disease specificity). The polygenic risk score method is used in several studies, with mixed results. Some studies report positive associations (for example (32–35)) while others did not find evidence that common genetic risk variation is shared between two traits (for example (36, 37)). This might be due to the size of the discovery sample (because the accuracy of the prediction score increases with the size of the discovery sample), or it may indicate a lack of genetic overlap.
