Chunk #27 — FROM GENE DISCOVERY TO POLYGENICITY: POLYGENIC AND WITHIN‐FAMILY APPROACHES TO ILLUMINATE MECHANISMS OF GENETIC RISK — Polygenic risk in a longitudinal framework
how this key social‐environmental factor might moderate genetic predispositions, and examined whether marriage confers a protective benefit against alcohol misuse when people get married relatively young. 128 In view of prior evidence that early marriage is associated with negative consequences across multiple domains including health, 131 , 132 we hypothesized that marriage may not have a protective effect when it occurs developmentally off‐time, meaning especially early. Consistent with our hypothesis, we found evidence that the way in which marriage moderates genetic influences on alcohol outcomes changes across development. Specifically, we found evidence for a pathogenic gene‐by‐environment interaction effect when people got married relatively early. Among those married at age 21, heavy episodic drinking was highest for those with higher polygenic scores compared to those with lower polygenic scores. Interestingly, this pathogenic gene‐by‐environment interaction effect decayed over time, such that by age 25 married individuals with higher polygenic scores engaged in no more heavy episodic drinking compared to those with a lower polygenic score.
