Our investigation initially examined association for 1430 SNPs, observing the strongest association with rs12364283, a functional D2 dopamine receptor gene (DRD2) promoter polymorphism (Zhang et al., 2007) that had not been examined previously in this context. Prior studies have observed that the rs12364283 minor (G) allele significantly impacts performance in behavioral tasks pertinent to PTSD (Frank and Hutchison, 2009; Hamidovic et al., 2009). One report (Hamidovic et al., 2009) observed that administration of amphetamines worsened the performance of rs12364283 minor (G) allele carriers on a behavioral inhibition task while improving the performance of non-carriers. We thus conducted additional analyses to examine whether greater risk is observed with the rs12364283 minor (G) allele in amphetamine dependent individuals.
