For decades, researchers have been discovering that your genes play a significant role in many aspects of your life, including the development of certain diseases. When you go to the doctor, someone is likely to ask you about your family’s medical history. Did someone in your family have heart disease, cancer, or hemophilia? If they did, your likelihood of developing those problems goes up significantly. But what about alcoholism? Sure, addiction is a disease, but it starts with behavior, so how can that be genetic? You may be surprised at what scientists have discovered when looking into the genetics of alcoholism and addiction. Learn more about the research into the question: is alcoholism genetic?
Human beings have been able to observe a link between alcoholism and family ties. Long-standing folk wisdom would say, “alcoholism runs in families.” Sure enough, scientific studies in the 1970s confirmed that alcoholism seemed to be passed down from one generation to the next. A study in 1974 found that adopted and nonadopted siblings that shared a parent with alcoholism both developed alcoholism later in life. The study also found that the severity of the parent’s alcohol use disorder also related to the development of alcoholism in offspring. Scientists have also looked at biological markers to find genetic associations with alcoholism. One study looked at dopamine receptors and how they might be able to predict a predisposition to alcoholism. The study confirmed an association but wasn’t able to observe a definitive link.
According to the National Institute on Drug Abuse (NIDA), a person’s biology and genetic factors make up about half of their addiction risk. Other biological variables that can influence your addiction risk factors can include sex, ethnicity, and the presence of mental disorders like depression, which can also be caused by genetic factors.
It’s true that addiction and alcohol use disorders do have environmental factors to them. A person that sees alcohol adds all the time, grows up in a house where alcohol is common, and starts drinking at an early age is much more likely to develop an alcohol use disorder than someone who doesn’t have early access to alcohol. Plus, the line between genetics and your environment can be blurred in the home. If your parents drank, do you drink because of their genes or because you learned their behaviors? The research shows that it’s a bit of both.
To study the genetics of alcoholism in a way that can be distinguished from environmental causes, researchers turn to two groups of people: twins and children that were adopted. Twins are important because identical twins develop when a single egg splits in the womb. Identical twins share almost completely identical genetics. On the other hand, fraternal twins develop from two separate eggs in the womb, and their genetic similarities are the same as any siblings.
Researchers compare the alcoholism histories of identical and fraternal twins. If alcoholism has a genetic component, it should show more in both identical twins more than it shows in both fraternal twins. A 1991 study found that where one identical twin had a history with alcoholism, the other would also have a similar history. Where one fraternal twin struggled with alcoholism, the other was less likely to have a similar history. It’s compelling evidence, but who’s to say environmental impacts still aren’t a factor?
One way researchers attempt to minimize environmental influences is to study adopted children. The children of people with alcohol use disorders that are adopted into non-drinking households are studied to look at the influence of genetics over environmental causes. If genetics play a significant role, then the adopted children of parents with alcoholism in non-drinking homes should still show a significant propensity towards alcohol use disorders. Several studies have shown that this is the case for adopted children, including one that studied 862 adopted men in Sweden.
Genetics seem to be a significant cause of addiction issues, but they might also help us find better treatment methods. Scientists are looking for ways to identify how genetics affect how you might respond to certain types of treatment. Addiction treatment is already tailored to your individual needs. But it can involve a lot of trial and error. Each week, your therapist will meet with you to analyze your treatment progress and make changes as they are needed. However, according to the National Institute on Alcohol Abuse and Alcoholism, researchers have been able to identify a specific gene that seems to predict how a person will respond to treatment with the drug naltrexone. If we are able to identify more genetic markers that can help form a better treatment plan for people with alcohol use disorders, treatment may become more effective and efficient.
Even though addiction and alcoholism are genetic, it doesn’t mean a substance use disorder is inevitable or untreatable. If you or someone you know is struggling with a substance use disorder, seeking addiction treatment can help them get out from under the oppression of active addiction. Alcoholism is often progressive, which means that it can get worse over time. Addiction can start to take over many aspects of your life, including your health, relationships, and finances. Early treatment can help prevent these consequences. But treatment can help address these problems no matter where you are in the disease of addiction. Learn more about treatment for alcoholism to begin your road to recovery today.
Cloninger, C. R. (1981, August 1). Inheritance of Alcohol Abuse. Retrieved from https://jamanetwork.com/journals/jamapsychiatry/article-abstract/492602
Cloninger, C. R. (1991, October 2). D2 Dopamine Receptor Gene Is Associated but Not Linked With Alcoholism. Retrieved from https://jamanetwork.com/journals/jama/article-abstract/392336
Goodwin, D. W. (1974, August 1). Drinking Problems in Adopted and Nonadopted Sons of Alcoholics. Retrieved from https://jamanetwork.com/journals/jamapsychiatry/article-abstract/491181
National Institute on Drug Abuse. (2018, June). Understanding Drug Use and Addiction. Retrieved from https://www.drugabuse.gov/publications/drugfacts/understanding-drug-use-addiction
National Institute on Alcohol Abuse and Alcoholism. (2018, September 21). Genetics of Alcohol Use Disorder. Retrieved from https://www.niaaa.nih.gov/alcohol-health/overview-alcohol-consumption/alcohol-use-disorders/genetics-alcohol-use-disorders
Pickens, R. W. (1991, January 1). Heterogeneity in the Inheritance of Alcoholism. Retrieved from https://jamanetwork.com/journals/jamapsychiatry/article-abstract/495189