Figure 6 and Table 1 summarize the results from our pooled analysis of Add Health and HRS. The GWAS-based polygenic scores have incremental R2’s of 1.00% for DEP, 1.27% for NEUR, and 1.20% for SWB. The corresponding MTAG-based polygenic scores all have greater predictive power: 1.17% for DEP, 1.65% for NEUR, and 1.57% for SWB. The proportional improvement in incremental R2 is in the range 17-30% for each trait, with 95% confidence intervals that do not overlap zero. The absolute levels of predictive power are clearly too small to be of clinical utility, but the improvements in R2 are close to those we would expect theoretically based on the observed increases in mean χ2-statistics (Online Methods). Polygenic scores based on trait-specific MTAG results have greater predictive power than scores based on MTAG results for the other traits (Figures 6c and 6d), consistent with the theoretical result that MTAG results can be interpreted as trait-specific estimates.
