Problematic alcohol use is a major public health concern with significant individual, family and societal impacts. It is estimated that alcohol use disorder impacts more than one in 10 adults in the U.S. each year. Both genetic factors and environmental factors (living conditions, education, experiences, etc.) contribute to the risk of alcohol use disorder. A new study in the American Journal of Psychiatry finds that environmental factors, everyday circumstances and experiences, have significantly greater influence on the risk for developing alcohol use disorder than genetics alone.

The Research

The researchers analyzed data from more than 11,000 individuals, including more than 5,000 each of African ancestry and European ancestry, to examine how genetic, psychiatric, and environmental factors predict alcohol use disorder.

They looked at data from interviews about experiences and mental health, and genetic risk information. Among the environmental factors they considered were education, attending religious services over the past 12 months, quality of relationship with primary childhood caregiver, exposure to early traumas and substance use in the household. They assessed mental health conditions, including major depression, posttraumatic stress disorder and anxiety. They also assessed polygenic risk scores, which use genetic information to assess a person’s chances of having or developing a particular medical condition.

Environmental Risk Factors

The study found that environmental risk factors accounted for the majority of the risk for alcohol use disorder, but genetic factors were also statistically significant. Among the environmental factors, less education, exposure to substance use in the household before age 13, lower household income and being male had the greatest influence on risk for alcohol use disorder. Among the mental health conditions, posttraumatic stress disorder was most associated with alcohol use disorder.

In general, the relationships with risk factors were the similar among people of European and African ancestry. However, the study found that among those of European ancestry, education level buffered the genetic risk, that is, people with higher education were more likely to have fewer alcohol use disorder symptoms even when their genetic risk was higher. This same relationship was not true among those of African ancestry.

Potential for Prevention

The authors note that these findings may help inform clinical, research, and policy efforts to minimize the risk of alcohol use disorder. The results suggest that addressing modifiable environmental and social factors could meaningfully contribute to preventing and reducing alcohol-related harms. Genetic information may be increasingly useful in the future as data accumulates and statistical power improves across community and clinical settings.