Spouses with uncontrolled drinking problems have a ‘large and rapid’ CAUSAL influence on the likelihood their partner will also be diagnosed with an alcohol use disorder. Reuters Health reports that this is according to a long-term study of married couples in Sweden.
After a husband was first diagnosed with alcohol use disorder (AUD), his wife’s risk of a similar diagnosis immediately rose 14-fold compared to women whose husbands did not have that diagnosis, researchers found. But then her risk fell during the next couple of years to about four-fold. Similarly, husbands’ risk shot up nine-fold after a wife’s diagnosis, then declined to about three-fold.
It’s long been known that spouses tend to resemble each other in alcohol consumption and abuse, the report says the study team writes, but it hasn’t been clear whether that’s because people with similar habits seek each other out, or because partners exert a strong influence on one another.
When the researchers looked at whether people had alcohol use disorders before their first marriage, and what happened in second and third marriages, they found that one spouse experiencing the disorder strongly influences the other’s current risk.
“Marriage partners can have a very substantial and causal effect on each other’s risk for AUD. In treating one married individual, you need to take their spouse into account,” lead author Dr Kenneth S Kendler, a professor of psychiatry and human and molecular genetics at Virginia Commonwealth University, in Richmond, is quoted in the report as saying.
About 15m adults in the US age 18 or older have alcohol use disorder, according to the National Institute on Alcohol Abuse and Alcoholism (NIAAA). An estimated 88,000 people with AUD die from alcohol-related causes annually, including liver damage, certain cancers and car crashes.
For the new analysis, which is the largest and first to look at risk over time and across multiple marriages, Kendler and his colleagues examined data collected from Swedish medical, criminal and pharmacy registries of residents born between 1960 and 1990. They identified 8,562 couples in first marriages with no history of alcohol use disorder in either partner prior to marriage and one spouse developing the disorder during the marriage.
The research team also studied 4,891 individuals with multiple marriages whose first spouse had no alcohol use disorder and second spouse did, or the reverse. When individuals transitioned from a first marriage to a spouse with an alcohol use disorder to a second marriage to a partner without the disorder, their risk for developing the disorder themselves was halved.
However, after a first marriage to a spouse without an alcohol use disorder, individuals who married a partner with the disorder raised their own risk seven- to nine-fold. A similar, but weaker risk increase was seen in third marriages with these combinations.
“The finding that marriage to a non-AUD spouse can be somewhat protective for individuals who subsequently marry spouses with AUD in one spouse and the risk of developing AUD in the other spouse is novel,” Dr Marcia Scott, a project officer in the NIAAA division of epidemiology and prevention research, said in the report.
Scott, who was not involved in the research, also said part of what makes this study unique is the focus on the temporal relationship between the development of AUD in one spouse and the risk of developing AUD in the other spouse.
Among the study’s limitations is that it is based on registry data and likely reflects a higher proportion of individuals more severely affected by medical and legal problems than other prior studies, the authors note.
Past research among twins and children of alcoholics has shown that genetic factors do influence alcoholism, they add. The current study indicates, though, that alcohol use disorders shared by married couples are not just a result of people seeking out mates who are similar to them in this regard, the authors write.
“Additional research can help to illuminate the interplay of social and genetic factors on risk and protective mechanisms of marital status on development of AUD across the lifespan, and the impact of these factors on couples’ children as well,” Scott said.
Importance: Although spouses strongly resemble one another in their risk for alcohol use disorder (AUD), the causes of this association remain unclear.
Objectives: To examine longitudinally, in first marriages, the association of a first registration for AUD in one spouse with risk of registration in his or her partner and to explore changes in the risk for AUD registration in individuals with multiple marriages as they transition from a spouse with AUD to one without or vice versa.
Design, Setting, and Participants: Population-wide Swedish registries were used to identify individuals born in Sweden between 1960 and 1990 who were married before the end of study follow-up on December 31, 2013. The study included 8562 marital pairs with no history of AUD registration prior to their first marriage and an AUD registration in 1 spouse during marriage and 4891 individuals with multiple marriages whose first spouse had no AUD registration and second spouse did or vice versa. Final statistical analyses were conducted from August 15 to September 1, 2017.
Exposures: A spousal onset or history of AUD registration.
Main Outcomes and Measures: Alcohol use disorder registration in national medical, criminal, or pharmacy registries.
Results: Among the 8562 marital pairs (5883 female probands and 2679 male probands; mean [SD] age at marriage, 29.2 [5.7] years) in first marriages, the hazard ratio of AUD registration in wives immediately after the first AUD registration in their husbands was 13.82, which decreased 2 years later to 3.75. The hazard ratio of AUD registration in husbands after the first AUD registration in their wives was 9.21, which decreased 2 years later to 3.09. Among the 4891 individuals with multiple marriages (1439 women and 3452 men; mean [SD] age at first marriage, 25.5 [4.2] years), when individuals transitioned from a first marriage to a spouse with AUD to a second marriage to a spouse without AUD, the hazard ratio for AUD registration was 0.50 (95% CI, 0.42-0.59) in women and 0.51 (95% CI, 0.44-0.59) in men. After a first marriage to a spouse without AUD, the hazard ratio for AUD with a second marriage to a spouse with AUD was 7.02 (95% CI, 5.34-9.23) in women and 9.06 (95% CI, 7.55-10.86) in men. These patterns were modestly attenuated when moving from second to third marriages. Controlling for AUD registration prior to first marriage or between first and second marriages produced minimal changes in risk.
Conclusions and Relevance: The increase in risk for AUD registration in a married individual following a first AUD registration in the spouse is large and rapid. When an individual with serial spouses is married, in either order, to partners with vs without an AUD registration, the risk for AUD registration is substantially increased when the partner has an AUD registration and decreased when the partner does not have an AUD registration. These results suggest that a married individual’s risk for AUD is directly and causally affected by the presence of AUD in his or her spouse.
Kenneth S Kendler, Sara Larsson Lönn, Jessica Salvatore, Jan Sundquist, Kristina Sundquist