Previous behavioral studies have reported that DRD2 SNPs predict avoidance-based decisions in healthy subjects [18], [19], [32]. Results from the current population confirmed that negative reinforcement learning linked with the ability to avoid maladaptative choices was associated with the DRD2 rs6277 SNP ( Fig. 1 ). There was an overall significant genotype difference, but there was no group or group x genotype interaction on Avoid B behavior. Subjects carrying the rs6277 A allele performed significantly better than G/G homozygous subjects on Avoid B pairs (p<0.005), but not for the positive Choose A performance. Other DRD2 and PENK SNPs examined did not influence reward learning performance in cannabis-dependent or control subjects, or in the whole sample. Inhibitory control as measured by SSRT was not modulated by any of the SNPs examined.
