Tom caught his very first glimpse of Ana on the last day of classes—she was trying to unchain her bike from a bike rack and clearly in a fit of frustration.

So, he stepped in and succeeded to free her ride. This gained him a smile and a quick number exchange… and eventually a first date and loving relationship too.

The two became attached at the hip and quickly fell in love; a couple years later, everyone began to bug them about a proposal and wedding dates, excited to see the relationship grow even further. But little did everyone know that their relationship wasn’t, in fact, on the rise any longer. Instead, it was plummeting—ever since Tom made a new friend that Ana refused to embrace: alcohol. A few months ago he started drinking nearly every day; and after just a couple weeks, their relationship began to suffer immensely.

Alcohol has proven time and time again its ability to drive a wedge into long-term relationships, as seen in one of many examples above. But researchers from Oregon Health and Science University sought to better understand the dynamic between drinking alcohol and two partners. So, they conducted a study “Alcohol’s Effects on Pair-Bond Maintenance in Male Prairie Voles” and observed the effects of alcohol on rodent partnerships. Their experiment revealed that relationships suffered when male prairie voles drank, but their female partners did not—which aligns with and potentially explains the interruption in human relationships. This research, published in Frontiers in Psychiatry, also found changes in the male voles’ brains.

“We know that in humans, heavy drinking is associated with increased separation rates in couples in which one of the partners is a heavy drinker and the other is not, while separation rates don’t seem to increase when both partners drink in a similar manner, or don’t drink at all,” explains one of the study’s authors, Andrey Ryabinin. But what’s not known is which causes the other: Do harmful drinking habits lead to a relationship’s demise or does the unhappiness that results from relationship difficulties drive one to drink?

To explore the answer to this perplexing question, researchers chose to experiment with prairie voles (a small rodent), as they are one of few rodent species that couple up and actually like to drink alcohol. The first step was to introduce male and female prairie voles to one another and allow them to develop relationships over the course of one week. Then, the researchers manipulated the couples in a few different ways: in some, only the male was granted access to an alcohol solution, while the female companion only received water; in others, both the male and female gained access to the alcohol; and in the control group, pairs were given only water.

It was then time to observe how the relationships were affected. Each male rodent was given the choice between cuddling up to his previous female partner or a new one—and based on how long the males spent next to either female, the researchers could determine the strength of the original relationship. They observed that males who drank alone spent less time with their original female partners, while those who never drank and those who drank with their partner spent more time with those original companions.

The researchers note that this resulting behavior mirrors how human actions transpire when it comes to alcohol’s effects on relationships and believe that it shows “discordant drinking” (whereas one partner drinks, and the other does not) can directly affect prairie voles’ relationships. They then continued experimentation and after analyzing the brains of the male prairie voles, found that there were, indeed, changes in a brain region called the periaqueductal grey in those who drank alone—which may just be responsible for the aforementioned effects.

While prairie voles were the sole subjects of this experiment, these findings give us better insight into human relationships and the effects alcohol may have on them: “Our results in prairie voles have identified a biological mechanism that could explain the link between discordant drinking and relationship breakdown, but we will need to do further work to confirm this for humans,” explained Ryabinin. He went on to say that future studies may yield even more promise, such that the negative effects of alcohol on relationships be confronted and potentially improved.

Sources: Frontiers (2017, November 17). When Male Voles Drink Alcohol But Their Partner Doesn’t, the Relationship Suffers. NeuroscienceNews. Retrieved November 17, 2017 from

Walcott, A. T., & Ryabinin A. E. (2017, November 17). Alcohol’s Effects on Pair-Bond Maintenance in Male Prairie Voles. Frontiers in Psychology. Retrieved November 20, 2017 from