Gene-based association with ADHD was estimated with MAGMA 1.0588 using the summary statistics from the European GWAS meta-analysis (Ncases = 19,099, Ncontrols = 34,194; Supplementary Information, Supplementary Information Table 1). Association was tested using the SNP-wise mean model, in which the sum of -log(SNP P-value) for SNPs located within the transcribed region (defined using NCBI 37.3 gene definitions) was used as the test statistic. MAGMA accounts for gene-size, number of SNPs in a gene and LD between markers when estimating gene-based P-values. LD correction was based on estimates from the 1000 genome phase 3 European ancestry samples34.
