developmentally relevant). It has been suggested that variants having a nominal association with an outcome are likely to be enriched for gene-by-environment interaction (Thomas, 2010). Accordingly, we focused our gene-by-environment analyses in adolescents on an externalizing disorder composite because we constructed our polygenic scores using estimates from a GWAS of an externalizing disorder composite in adults. We used p < 0.05 as suggestive evidence for association and moderation because our tests were not independent (owing to correlated phenotypes) and a Bonferroni correction would be too stringent.
