According to the results of a new study, conducted by researchers from Virginia Commonwealth University and Rutgers University, romantic partners can influence a person’s genetic predisposition to problematic alcohol use. Specifically, its findings demonstrate that the substance use habits, personality traits, and mental health status of individuals’ long-term partners can increase or reduce the impact of their genetic risk for binge drinking. Importantly, the study’s results could help create effective strategies for couples therapy and couple-based alcohol interventions.
“This research sheds new light on the complicated and unforeseen ways that spouses and long-term partners can shape our health and well-being,” said Dr. Mallory Stephenson, a postdoctoral fellow at the Virginia Institute for Psychiatric and Behavioral Genetics within the VCU School of Medicine, in a news release.
It is currently thought that an individual’s genetic makeup accounts for approximately 50% of their risk for alcohol use disorder and other forms of risky drinking. However, the influence of these genetic factors can change depending on one’s environment.
“For example, if a person has a high genetic risk for alcohol use disorder and experiences a traumatic event, such as the death of a close relative or exposure to a natural disaster, their biology could play more of a role in whether or not they develop an alcohol problem in response to that stressor,” Dr. Stephenson added. “However, if that person isn’t experiencing anything stressful in their life, their genetic risk may not have as much influence on their drinking behavior.”
Previous research carried out at VCU had shown that people who are genetically prone to risky alcohol use may drink less when in relationships, while the present study explored how specific partner traits influence that risk.
To investigate the impact of partner traits on genetic risk for alcohol problems, researchers analyzed data from 1,620 Finnish twins and their romantic partners—focusing on substance use, personality, and mental health. “Twin studies are a really useful tool to disentangle the genetic and environmental influences on our lives,” Dr. Stephenson said. “By studying fraternal twins, which share 50% of their genetic makeup, and identical twins, which share 100% of their genetic makeup, we can gain insights into how genetic and environmental factors interact with each other and play a role in developing certain behaviors.”
The study results showed that individuals in early midlife are significantly more likely to drink heavily if their romantic partners also drink or smoke frequently, especially among men. However, they also demonstrated that certain partner traits—such as frequent smoking, low conscientiousness, high extroversion, neuroticism, and psychological distress, can also increase a person’s genetic risk for binge drinking. Surprisingly, having a partner who drinks more often was linked to a weaker expression of genetic risk, suggesting that partner behaviour may shape environmental influences more than genetic ones. The study was funded by the National Institute on Alcohol Abuse and Alcoholism, which is part of the National Institutes of Health (NIH), as well as by the Academy of Finland.
