Table 4. Association between chronic pain in Generation Scotland and UK Biobank and polygenic scores for MDD derived using data from the Psychiatric Genomic Consortium.

Polygenic score	Chronic Pain Grade in Generation Scotland	Chronic Pain Grade in UK Biobank
MDD score pT = 0.01	β = 2.81 x 10−2 (95%CI -5.56 x 10−3 to 6.22 x 10−2), p = 9.7 x 10−2	β = 1.56 x10-2 (95%CI 6.36 x 10−3 to 2.60 x 10−2), p = 1.5 x 10−3
MDD score pT = 0.05	β = 5.49 x 10−2 (95%CI 2.40 x 10−2 to 9.16 x 10−2), p = 1.70 x 10−3	β = 2.27 x 10−2 (95%CI 1.27 x 10−2 to 3.21 x 10−2), p < 3 x 10−4
MDD score pT = 0.1	β = 6.62 x 10−2 (95%CI 2.82 x 10−2 to 9.76 x 10−2), p = 4.3 x 10−4	β = 2.56 x 10−2 95%CI 1.62 x 10−2 to 3.63 x 10−2, p < 3 x 10−4
MDD score pT = 0.5	β = 5.07 x 10−2 (95%CI 1.69 x 10−2 to 8.35 x 10−2), p = 1.3 x 10−3	β = 2.35 x 10−2, 95%CI 1.47 x 10−2 to 3.37 x 10−2, p < 3 x 10−4

MDD: Major Depressive Disorder. pT represents the p-value threshold (in the independent discovery GWAS sample) used to calculate the polygenic risk score. β represents standardised regression coefficient between the four polygenic risk scores and the two chronic pain phenotypes. All analyses were conducted in MCMCglmm. The 95% CI represents the 95% credible interval, which is broadly interpreted as the interval in which there is a 95% probability that the true parameter lies.