Chunk #26 — FROM GENE DISCOVERY TO POLYGENICITY: POLYGENIC AND WITHIN‐FAMILY APPROACHES TO ILLUMINATE MECHANISMS OF GENETIC RISK — Polygenic risk in a longitudinal framework
The COGA prospective sample data enables exploration of important, longstanding questions in the field of addiction, such as the roles of predispositional liability versus the neurotoxic effects of substances (see, 3. Brain Function for a summary of these findings), or the ways in which interactions between genetic and environmental factors are associated with relevant outcomes across development. In one such example of the latter, we examined whether a key social‐environment factor (marriage) moderated polygenic influences on heavy episodic drinking. 128 Marriage is associated with reductions in alcohol consumption and risk for AUD in multiple independent samples, 129 and in an earlier analysis of a sample of Australian female–female twin pairs, marriage moderated genetic influences on alcohol consumption such that genetic influences were more pronounced when women were unmarried versus married. 130 We brought a developmental lens to the question of 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
