The iPSYCH2012 sample will be able to leverage single-nucleotide polymorphism -derived, genome-wide metrics such as disease-specific polygenic risk scores.74, 75, 76 These provide a continuous measure of liability (rather than a categorical measure of family history), which will greatly enhance our ability to combine genetic, environmental and phenotypic data in disease prediction. We have found higher polygenic loading for schizophrenia in both cases and controls with family histories of mental disorders.77 Also 48% of the effect associated with family history of psychoses was mediated through the polygenic risk score for schizophrenia.78 To further explore the association between the risk of schizophrenia and the polygenetic risk score for schizophrenia, we have investigated the interplay with infections,79 treatment resistant schizophrenia,80 chronicity of schizophrenia,73 and mortality and suicidal behaviour.81
