Pre-test baseline differences and frequencies for the CNR1 and FAAH SNPs are presented in Table 1. The frequencies of the SNPs were consistent with previous reports and both SNPs were in Hardy–Weinberg equilibrium. Because, for each SNP, only a few individuals were homozygous for the minor allele, these individuals were combined with the heterozygote group to form one group that was then compared with the group that was homozygous for the common allele. The FAAH and CNR1 SNPs were not in linkage disequilibrium. Analysis of the effects of cannabis withdrawal utilized a 2 (abstinence: pre-abstinence versus post-abstinence) × 2 [genotype: CNR1 T/T versus CNR1 T/C (T/C and C/C) or FAAH C/C versus C/A (C/A and A/A)] mixed analyses of variance where trial was a within-subjects factor and genotype was a between-subjects factor. Analysis of the effects of cue-exposure utilized a 3 (cue: pre-abstinence, pre-cue exposure versus post-abstinence, pre-cue exposure versus post-abstinence, post-cue exposure) × 2 (genotype: CNR1 T/T versus CNR1 T/C or FAAH C/C versus C/A) mixed analysis of variance where cue was a within-subjects factor and genotype was a between-subjects factor. SAS version 9.1 was used to conduct all analyses.
