PRS that embody genome-wide risk for a trait can, depending on the GWAS data available on which the PRS is based, be used to predict risk in any array-genotyped individual and the statistical significance of this prediction can be measured. Current PRS studies identified several significant associations between SUD genetic liability and a wide range of psychiatric and behavioral traits. However, there is still a wide gulf between a statistically significant prediction of risk and one that is clinically useful on an individual level. At this point, we have not yet approached clinical utility for PRS in risk prediction, and although some commercial tests have been marketed that purport to do exactly that, we view them skeptically, and where evaluated rigorously, they have failed to hold up. For example one test that purports to predict OUD risk, actually predicts not the subject’s OUD risk but his or her ancestral population97.
