We evaluated the comparability of the seven cohorts by estimating the common-variant genetic correlations (rg) between them. These analyses strongly supported the comparability of the seven cohorts (Supplementary Table 3) as the weighted mean rg was 0.76 (SE 0.03). The high genetic correlations between the 23andMeD and other cohorts are notable. While there is no statistical evidence of heterogeneity in the rg estimates between pairs of cohorts (P=0.13), the estimate is statistically different from 1 which may reflect etiological heterogeneity. This estimate can be benchmarked against the slightly larger weighted mean rg between schizophrenia cohorts of 0.84 (SE 0.05)21.
