controls) in order to highlight the importance of discovery sample size in GPRS predictive performance(43): GPRS-SCZ1 predicted at best up to 0.5% of the variance on MDD liability. In order to further confirm these findings, we used the equations based on genetic quantitative theory developed by Dudbridge(43) in order to estimate the expected predictive accuracy of GPRS Pt<0.5 (the best performing threshold) as a function of parameters such as discovery sample size (Supplemental Methods). The theoretical estimates of explained variance were highly convergent (GPRS-MDD 0.5%, GPRS-BIP 0.3%, GPRS-SCZ2 1.2%, GPRS-SCZ1 0.3%) with the empirical values of explained variance obtained in the present study. More interestingly, a model assuming GPRS-MDD based on a discovery sample of the same size of SCZ2 indicated that an even larger amount of variance explained in MDD liability could be expected (3%).
