One fascinating empirical development has been the emergence of the “profile score” concept, an extreme form of the CDCV model. In a recent Nature paper (International Schizophrenia Consortium, 2009), the authors developed a list of ~30,000 SNPs and their risk alleles in one large schizophrenia case-control sample. This list can be used to compute a risk profile for each person in independent samples (i.e., the number of schizophrenia risk alleles). The score from the initial sample significantly predicted schizophrenia risk in three independent samples (p-values 2×10−28, 5×10−11, and 0.008), bipolar risk in two independent samples (p-values 1×10−12 and 9×10−9), and, crucially, was not associated with risk of six non-psychiatric biomedical disorders (Crohn’s disease, T1DM, T2DM, coronary artery disease, hypertension, and rheumatoid arthritis). These data strongly support the CDCV model and also suggest genetic overlap between schizophrenia and bipolar disorder.
