schizophrenia from other psychosis diagnoses (Nagelkerke’s R2 of 9% and those in the top quintile of PRS having an approximately 2-fold increased risk of being subsequently diagnosed with schizophrenia) [24]. This is a low predictive ability, but the setting within first-episode psychosis cases makes it more appealing because (1) it does not require genotyping of the general population, only people with psychosis, and (2) it is not relevant to major decisions (like treat/not treat), but could provide additional information potentially useful for the care plan. In addition to assisting diagnosis, genotype data could be used to calculate other PRS in secondary screening, for example, cardiovascular disease, since psychosis cases are already at high cardiometabolic risk.
