Analyses of the withdrawal scale revealed a significant effect for abstinence, F(1,96) = 35.55, P < 0.0001, such that withdrawal increased significantly after 5 days of abstinence. Analysis of the CNR1 SNP revealed a significant abstinence × genotype interaction, F(1,96) = 6.71, P < 0.012, indicating that T/C individuals demonstrated greater withdrawal after abstinence (see Fig. 1). There was a trend towards a main effect for the CNR1 SNP P < 0.082. Analysis of the FAAH SNP did not reveal any significant effects.
