The second aim was to investigate possible interaction between the previously published common risk gene variants of ADHD in the ADGRL3 (=LPHN3) gene (rs2305339, rs1397548, rs734644, rs1397547, rs2271338, rs6551665, and rs2345039) and shared risk gene variants of aADHD and BD in the DGKH gene (DGKH rs994856/rs9525580/rs9525584 GAT haplotype) and pre-, peri-, and postnatal risk factors in comparison to a healthy control group.