Effect of Marriage on Risk for Onset of Alcohol Use Disorder: A Longitudinal and Co-Relative Analysis in a Swedish National Sample.

OBJECTIVE: The authors sought to clarify the relationship between marriage and risk for alcohol use disorder.

METHOD: The association between marital status and risk for first registration for alcohol use disorder in medical, criminal, and pharmacy registries was assessed in a population-based Swedish cohort (N=3,220,628) using longitudinal time-dependent survival and co-relative designs.

RESULTS: First marriage was associated with a substantial decline in risk for onset of alcohol use disorder in men (hazard ratio=0.41, 95% CI=0.40-0.42) and women (hazard ratio=0.27, 95% CI=0.26-0.28). This association was slightly stronger when the spouse had no lifetime alcohol use disorder, while marriage to a spouse with lifetime alcohol use disorder increased risk for subsequent alcohol use disorder registration in both men (hazard ratio=1.29, 95% CI=1.16-1.43) and women (hazard ratio=1.18, 95% CI=1.06-1.30). In both sexes, the protective effect of marriage was significantly stronger in those with than those without a family history of alcohol use disorder. In both men and women, the associations between marriage and risk for alcohol use disorder in cousins, half siblings, full siblings, and monozygotic twins discordant for marital status were as strong as that seen in the general population.

CONCLUSIONS: First marriage to a spouse with no lifetime alcohol use disorder is associated with a large reduction in risk for alcohol use disorder. This association cannot be explained by standard covariates or, as indicated by co-relative analyses, familial genetic or shared environmental confounders. These results are consistent with the hypothesis that the psychological and social aspects of marriage, and in particular health-monitoring spousal interactions, strongly protect against the development of alcohol use disorder. The protective effects of marriage on risk for alcohol use disorder are increased in those at high familial risk for alcoholism.