Pattern of interaction between galanin-2 receptor SNP and residual pain upon 12-month mood score. SNP rs8836 showed a significant interaction term in the recessive model (p = 0.003, uncorrected for multiple tests). The 12 month SF-36 MH mood scores are plotted against the mean of bodily pain scores at 3 and 6 mos. Each point is the mean 12-month mood for all of the patients with that bodily pain score and genotype. The curve connecting the triangles represents 33 patients homozygous for the uncommon allele; the curve connecting the filled circles represents 93 patients with one or no copies of the uncommon allele. In the presence of high residual postoperative pain, 2 copies of the uncommon allele appear to be associated with relative protection against symptoms of depression and anxiety, but the small numbers of such patients make this result illustrative, not statistically persuasive.
Max et al. Molecular Pain 2006 2:14 doi:10.1186/1744-8069-2-14