In order to investigate the possibility of the risk locus at chromosome 8, being a general risk locus for psychiatric disorders we conducted a cross-disorder GWAS based on the same individuals as included in the CUD GWAS. All individuals with a diagnosis of schizophrenia (ICD10 code F20), bipolar disorder (ICD10 codes F30-F31), attention-deficit hyperactivity disorder (ICD10 code F90.0), autism spectrum disorder (ICD10 codes F84.0, F84.1, F84.5, F84.8, F84.9) and major depressive disorder (ICD10 codes F32-F33) were used as cases, in total 35,006 individuals and 16,366 individuals without any of the listed psychiatric disorders were used as controls. The GWAS was conducted using wave as covariates and PCs from PCA (generated as described for the CUD GWAS).
