How do genes influence alcohol use disorder?
Alcohol use disorder (AUD) often seems to run in families, and we may hear about scientific studies of an “alcoholism gene.” Genetics certainly influence our likelihood of developing AUD, but the story isn’t so simple.
Research shows that genes are responsible for about half of the risk for AUD. Therefore, genes alone do not determine whether someone will develop AUD. Environmental factors, as well as gene and environment interactions account for the remainder of the risk.
Multiple genes play a role in a person’s risk for developing AUD. There are genes that increase a person’s risk, as well as those that may decrease that risk, directly or indirectly. For instance, some people of Asian descent carry a gene variant that alters their rate of alcohol metabolism, causing them to have symptoms like flushing, nausea, and rapid heartbeat when they drink. Many people who experience these effects avoid alcohol, which helps protect them from developing AUD.**
As we have learned more about the role genes play in our health, researchers have discovered that different factors can alter the expression of our genes. This field is called epigenetics. Scientists are learning more and more about how epigenetics can affect our risk for developing AUD.
Can our genes affect alcohol treatment?
Scientists are also exploring how genes may influence the effectiveness of treatments for AUD. For instance, the drug naltrexone has been shown to help some, but not all, patients with AUD to reduce their drinking. Research has shown that patients with AUD who also have variations in a specific gene respond positively to treatment with the drug, while those without the specific gene do not. A fuller understanding of how genes influence treatment outcomes will help doctors prescribe the treatment that is most likely to help each patient.***
What is NIAAA doing to learn more?
NIAAA has funded the Collaborative Studies on Genetics of Alcoholism (COGA) since 1989, with the goal of identifying the specific genes that influence alcohol use disorder. In addition, NIAAA funds investigators’ research in this important field, and also has an in-house research emphasis on the interaction of genes and the environment. NIAAA is committed to learning more about how genes affect AUD so that treatment—and prevention efforts—can continue to be developed and improved.