Diagnostic groups were compared on age and the percentage of African ancestry (i.e., using a STRUCTURE-estimated ancestry proportion score) using ANOVA and on sex and the psychiatric diagnoses using a 2×2 contingency table and the χ2 test. Association between gender and SNP genotype was examined using the chi-square test and the association between age and SNP genotype was studied using ANOVA. Linkage disequilibrium (LD) plots, haplotype blocks, and tests of Hardy-Weinberg equilibrium for each group were generated using the software program Haploview v3.32 (Barrett et al. 2005).
