Table 3. Association between MDD-related traits in GS:SFHS and UK Biobank with the Psychiatric Genomics Consortium derived MDD polygenic risk scores.

PGRS score	MDD in GS:SFHS	MDD in UK Biobank
MDD score pT = 0.01	β = 3.18 x 10−2 (95%CI -1.56 x 10−2 to 7.28 x 10−2), p = 0.21	β = 4.90 x 10−2 (SE = 1.34 x 10−2), p = 2.6 x 10−4
MDD score pT = 0.05	β = 7.44 x 10−2 (95%CI 2.71 x 10−2 to 1.18 x 10−1), p = 2.1 x 10−3	β = 7.02 x 10−2 (SE = 1.35 x 10−2), p = 2.1 x 10−7
MDD score pT = 0.1	β = 9.75 x 10−2 (95%CI 4.53 x 10−2 to 1.35 x 10−2), p ≤ 2 x 10−4	β = 7.38 x 10−2 (SE = 1.37 x 10−2), p = 6.4 x 10−8
MDD score pT = 0.5	β = 9.68 x 10−2 (95%CI 4.48 x 10−2 to 1.33 x 10−1), p ≤ 2 x 10−4	β = 6.11 x 10−2 (SE 1.37 x 10−2), p = 8.10 x 10−6

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 MDD in GS:SFHS and UK Biobank. 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.