The rs1049353 polymorphism in the CNR1 gene interacts with childhood abuse to predict posttraumatic threat symptoms.

aError bars represent standard error of the mean. Determination of low vs high level of childhood physical abuse (CPA) was based on summing the items of the Conflict Tactics Scale and dichotomizing based on a median split; GG/low CPA n = 203, GG/high CPA n = 194, AG/AA/low CPA n = 43, AG/AA/high CPA n = 47. Genotype frequencies were as follows: A/A (n = 7 [1.4%]), A/G (n = 83 [17.0%]), G/G (n = 397 [81.6%]); they did not deviate from Hardy-Weinberg equilibrium (χ1 = 1.20, P = .27). Results of a multivariate analysis of covariance revealed a significant rs1049353 genotype × CPA interaction in predicting threat symptoms only (F1,454 = 7.57, P = .006). An additional CNR1 single-nucleotide polymorphism (SNP)—rs806368—which has been implicated in PTSD,6 was also examined alone and interactively with CPA in relation to the severity of threat and loss symptoms. Although there was a marginal main effect of rs806368 genotype (minor allele carrier vs not) on severity of threat symptoms (F1,453 = 4.37, P = .037), it did not withstand the correction for multiple comparisons of 2 SNPs (P = .025). rs806368 genotype was also not related to loss symptoms (F1,453 = 2.99, P = .085), nor was the interaction of this polymorphism and CPA related to threat or loss symptoms (F values < 2.47, P values > .117). –0.4 –0.3 –0.2 –0.1 0 0.1 0.2 0.3 0.4