AD was also strongly genetically correlated with poor educational and socioeconomic outcomes, and marginally correlated with measures of risk-taking. Nominally significant genetic correlations with delay discounting (i.e. favoring immediate rewards), risk-taking, and the strong genetic correlation of AD with ADHD, cigarette smoking and cannabis use may similarly reflect a shared genetic factor for risk-taking and reduced impulse control. Common genetic liability to early, risky behaviors is characteristic of both AD39 and age of first birth40. The observed negative genetic correlation with age of first birth is consistent both with risk-taking and with the significant genetic correlations of AD with lower socioeconomic status, as indexed by higher neighborhood Townsend deprivation score, and lower educational attainment. Lower socioeconomic status is correlated with both AD41 and age at first birth42 and the current study suggests that shared genetic liabilities may be one potential mechanism for their observed relationship. However, the question of whether these genetic correlations represent causal processes, horizontal pleiotropy, or the impact of unmeasured confounders should be explored in the future43.
