Finally, we meta-analyzed the ADHD GWAS with each replication cohort. For EAGLE/QIMR, we developed a novel model to meta-analyze the GWAS of the continuous measure of ADHD with the clinical diagnosis in the ADHD GWAS. In brief, we perform a Z-score based meta-analysis using a weighting scheme derived from the SNP heritability and effective sample size for each phenotype that fully accounts for the differences in measurement scale (detailed description in Supplementary Information, and Supplementary Figures 18–20). This calibration based on the genome-wide estimate of heritability prevents joint meta-analysis of all replication cohorts since genome-wide data is not available for the deCODE study.
