We observed a functional DRD2 promoter polymorphism (rs12364283) (Zhang et al., 2007) to be the SNP most highly associated with PTSD in our sample. However, the p value for this association was not significant when a stringent Bonferroni correction for multiple comparisons was applied. Further analyses revealed that this association is largely limited to amphetamine dependent individuals. We found that controlling for self-reported impulsivity resulted in only a mild reduction in estimated risk.
