Using a developmental perspective to examine the moderating effects of marriage on heavy episodic drinking in a young adult sample enriched for risk

Abstract

Many studies demonstrate that marriage protects against risky alcohol use and moderates genetic influences on alcohol outcomes; however, previous work has not considered these effects from a developmental perspective or in high-risk individuals. These represent important gaps, as it cannot be assumed that marriage has uniform effects across development or in high-risk samples. We took a longitudinal developmental approach to examine whether marital status was associated with heavy episodic drinking (HED), and whether marital status moderated polygenic influences on HED. Our sample included 937 individuals (53.25% female) from the Collaborative Study on the Genetics of Alcoholism who reported their HED and marital status biennially between the ages of 21 and 25. Polygenic risk scores (PRS) were derived from a genome-wide association study of alcohol consumption. Marital status was not associated with HED; however, we observed pathogenic gene-by-environment effects that changed across young adulthood. Among those who married young (age 21), individuals with higher PRS reported more HED; however, these effects decayed over time. The same pattern was found in supplementary analyses using parental history of alcohol use disorder as the index of genetic liability. Our findings indicate that early marriage may exacerbate risk for those with higher polygenic load.

Keywords: alcohol; development; genetics; marital status; young adults.

Figure 1:

Heavy episodic drinking as a function of the three-way interaction of Alc-PRS, marital status, and time. Notes. CIs are not symmetric because they were converted from expected log-transformed counts. The first three ancestral principal components and sex were included as covariates. HED frequency was measured in days over the last 12 months. Abbreviations: CI = Confidence interval; HED = Heavy episodic drinking; PRS = Genome-wide polygenic risk score for alcohol.

Figure 2.

Heavy episodic drinking as a function of the three-way interaction between parental history of alcohol disorder, marital status, and time. Notes. CIs are not symmetric because they were converted from expected log-transformed counts. The first three ancestral principal components and sex were included as covariates. HED frequency was measured in days over the last 12 months. Abbreviations: CI = Confidence interval; HED = Heavy episodic drinking; PHAD = Parental history of alcohol disorder.