Certain traits in romantic partners can amplify impact of person’s genetic risk for alcohol problems, VCU-led research shows

RICHMOND, Va. (WRIC) -- A study led by Virginia Commonwealth University (VCU) has found that the personality traits, substance use habits and mental health status of long-term partners can enhance or diminish the impact of a person's genetic risk for binge drinking.

According to VCU, findings from the study, which was co-led by Rutgers University researchers, could help reshape 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 Mallory Stephenson, Ph.D., a postdoctoral fellow within VCU's School of Medicine.

The university said a person’s genes account for roughly half of their risk for alcohol use disorder and other forms of risky drinking, but the influence of these genetic factors can change depending on a person’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,” Stephenson said. “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.”

In the study, researchers aimed to better understand whether any particular characteristics shown by a romantic partner can impact a person’s genetic risk for drinking. To answer this question, the team of researchers examined data from a longitudinal study of anonymous twins from Finland’s Central Population Registry.

Researchers specifically looked at Finnish twins in their 30s who were in long-term relationships and had a history of alcohol use. They analyzed survey responses from 1,620 twins and their romantic partners, including responses on their drinking and smoking habits, personality characteristics and mental health status. 

“Twin studies are a really useful tool to disentangle the genetic and environmental influences on our lives,” Stephenson said. “By studying fraternal twins, which share 50% 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.”

VCU said the study's findings were consistent with previous studies, including that a person in early midlife was more likely to drink alcohol and binge drink if their romantic partner also frequently drank alcohol or smoked cigarettes.

In addition, the study further found that genetic risk for binge drinking had a greater effect in people whose romantic partners smoked cigarettes more often, were less conscientious, were more extroverted or reported higher neuroticism or psychological distress.

Conversely, the university said the heritability of binge drinking had less of an effect on people whose partners reported more frequent alcohol use, which reportedly surprised the research team. 

“Even if you have a good relationship with your partner, this research shows that their substance use, personality traits and mental health can still have an impact on you,” Stephenson said.