Liability scale hSNP2 statistics were estimated for case/control phenotypes (i.e. PTSDf2, AUD and AD) and observed scale hSNP2 statistics were estimated for the non-case/control phenotypes, in EA and AA summary statistics. Table 1 shows the computed hSNP2 estimates for those of EA and AA from GWASs used for the analyses below. Notably, prior work suggests a general Z score cut off of 4 for heritabilities to determine that traits are appropriate for genetic correlation (Bulik-Sullivan et al., 2015a). Estimates within Table 1 with Z scores below 4 are shaded, and should be interpreted with caution. Online Supplementary Fig. S1 depicts the h2 SNP Z scores for all included samples. All but one of the Z scores in EA samples is above 4. In contrast, only 1 of the Z scores is greater than 4 in AA samples suggesting these estimates are not robust.
