The results of the polygenic risk score analyses are presented in Figure 5. In the NTR, polygenic risk scores are significantly (P<0.05) associated with neuroticism when polygenic scores are based on SNP sets with P-value thresholds of 1 × 10−3 and lower. The most significant result was found for the SNP set with a P-value threshold of 0.05, with an explained variance of 0.66% and a P-value of 1.09 × 10−12. In the combined NTR/NESDA cohort, polygenic risk scores are significantly (P<0.05) associated with MDD for SNP sets with P-value thresholds of 0.01 and 0.05, with higher neuroticism predicting larger risk for MDD. The most significant result was found for the SNP set with a P-value threshold of 0.05, with an explained variance of 1.05% and a P-value of 4.02 × 10−9.
