VCU news

By VCU News staff

Genetic risk for alcohol misuse may be transmitted across generations through exposure to parental discord or divorce, according to a study co-led by a Virginia Commonwealth University doctoral student and a Rutgers University researcher.

Nate Thomas, a fifth-year student in the Ph.D. in Developmental Psychology program at VCU’s College of Humanities and Sciences, co-authored the study, published last month in Molecular Psychiatry, which found that children’s exposure to parents’ relationship discord or divorce is associated with the potential for alcohol use disorder as adults.

“We found evidence of indirect genetic effects that contribute to the etiology (causes) of alcohol use disorder,” Thomas said. “Genetic liability for alcohol use disorder in parents influences their own likelihood of divorce and marital discord. Divorce and marital discord in parents goes on to influence their offspring’s likelihood of experiencing alcohol use disorder later in life.”

Thomas co-authored the study with Jessica Salvatore, Ph.D., an associate professor and director of the Genes, Environments and Neurodevelopment in Addictions Program at Rutgers’ Robert Wood Johnson Medical School who previously worked at VCU.

“Previous research has shown that genes that predispose people to alcohol use disorder also predispose them to experience more conflict in their close romantic relationships,” Salvatore said. “Based on this, we hypothesized that children who are exposed to divorce or parental relationship discord also inherit a genetic predisposition toward alcohol problems — and that experiencing these family adversities might be one pathway through which genetic risk for alcohol problems is passed from parents to their children.”

The researchers used the Collaborative Study on the Genetics of Alcoholism – a large-scale family study designed to identify genes that affect the risk for alcohol use disorder and alcohol-related behaviors – and analyzed data from 4,846 people of European ancestry and 2,005 people of African ancestry who were interviewed when they were approximately age 30. They assessed whether participants had any symptoms of DSM-5 Alcohol Use Disorder. They also studied predictors in their parents, including relationship discord, divorce and alcohol use disorder symptoms, and measured their genetic predispositions for alcohol problems.

In families of European descent, researchers found evidence that parental variations of genes associated with increased risk of alcohol problems also increased the likelihood that children in those families would experience parental relationship discord and divorce, which were in turn associated with riskier alcohol behaviors from drinking at earlier ages to greater lifetime maximum drinks and a greater likelihood of developing alcohol use disorder symptoms. Importantly, these effects were observed even when parents’ own alcohol use behaviors were statistically controlled for in the model.

The study did not find this evidence in people with African ancestry, and Salvatore said further research is needed to determine why.

This story, shared with permission, includes reporting from Rutgers University. Read more about this study on Rutgers University’s website.