Prediction analyses were performed using the National Longitudinal Study of Adolescent to Adult Health (Add Health), the Health and Retirement Study (HRS), and the Wisconsin Longitudinal Study (WLS). Polygenic scores were constructed using HapMap3 SNPs that meet the following conditions: (i) the variant has a call rate greater than 98% in the prediction cohort; (ii) the variant has a minor allele frequency (MAF) greater than 1% in the prediction cohort; and (iii) the allele frequency discrepancy between the meta-analysis and the prediction cohort does not exceed 0.15. To calculate the SNP weights we use the software package LDpred25, assuming a fraction of causal variants equal to 1, and then we construct the scores in PLINK.
