The Genetics of Alcoholism

A certain combination of hundreds of genes in individual’s DNA can increase the risk of developing alcoholism. What are the ‘alcoholic genes’ that put you at risk? A brief review here.

10
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ARTICLE OVERVIEW: Scientists still have not identified the combination of genes thought to increase risk of alcohol problems. In this article, we outline the possible risk factors and share some tips on how to protect yourself if you are genetically predisposed to becoming an alcoholic. Then, we welcome your questions at the end.


ESTIMATED READING TIME: 10 minutes.


TABLE OF CONTENTS:


Alcohol Addiction and Genetics

Alcohol is the #1 drug in the world. It’s consumed everywhere, from places of work to places of worship. But what can be causing alcoholism? And do your genes have something to do with it?

Maybe.

Genes are passed on by our parents, and some of those genes contain predisposition towards alcohol use disorder (AUD) and alcoholism. But just how much those genes influence us is still up for debate. According to the study Genetics and Alcoholism alcoholism is a complex genetic disease, with variations in a large number of genes affecting risk. So, what puts some people more at risk than others?

Most of us can see that alcohol use disorder run in some families. For example, if you have a drinking problem and create a Family Map, you can probably identify multiple people across many generations that also struggle with alcohol. Further, among people who drink too much, those who are genetically predisposed have a higher risk of developing alcohol use disorder.

However, even though people can have ‘the alcoholic gene’, it doesn’t mean that they will become alcohol dependent. Social and environmental factors play a huge role in becoming an addict.

In sum, it is true that our genetic structure determines human traits such as physical characteristics (eye and hair color) and behavioral characteristics, including aggression and depression. But the truth is that there are many factors that create the perfect environment for alcohol problems. And our genes DO NOT INFLUENCE US AS MUCH AS WE THINK.

Main Genetic Studies

It ihas been established that genetics is responsible for alcohol use disorder about 50% of the time. However, genetic expression is more complex field then we think. How genetic material can influence the ‘final product’ of one person is still unknown. So, what landmark studies back this up?

There are numerous studies that work on identifying the genes that can lead to alcoholism. The DRD2 gene was the first gene that showed promise of revealing the connection of alcoholism and genetics. Also, researchers at  the University of California in San Francisco UCSF are studying the fruit flies to find the genetic traits of alcoholism claiming that drunken fruit flies behave in the same way humans do when they drink.

According to this study funded by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), Genetic Research: Who Is At Risk for Alcoholism? researchers concluded that many twin, adoption, and family studies conclusively demonstrated that genetic factors account for 50 to 60 percent of the variance in risk for developing alcoholism.

And to move the field forward, the NIAAA started the Collaborative Studies on Genetics of Alcoholism (COGA), a large–scale family study designed to identify genes that affect the risk for alcoholism and alcohol–related characteristics and behavior. COGA holds data on more than 2,255 extended families and more than 17,702 individuals that struggle with alcoholism.

If you like to learn more about the main studies that contributed to this topic check out this collection of studies: A Brief History Of Research on the Genetics of Alcohol and Other Drug Use Disorders. 


Certain combinations of genes that hold alcohol dependency material may increase your risk of developing alcoholism. 


The “Alcoholic Gene”

Do you believe that only one gene is responsible for inheriting alcoholism?

You are wrong!

There are hundreds of genes in one’s DNA that can increase the risk of developing an alcohol use disorder. Each gene plays a different role in your personal traits, and certain combinations of these genes may hold the key of alcoholism. The study Genes Contributed to The Development of Alcoholism claims that the genes most strongly implicated are those encoding the key enzymes of alcohol metabolism: ADHs and ALDHs.

Moreover, COGA lists several genes that are connected to the development of alcoholism. These can include:

DNA Regions with Susceptibility Genes. Genetic analysis has provided evidence that regions on 3 chromosomes contain genes that increase the risk for alcohol use disorder. Regions on chromosomes 1 and 7 have the strongest evidence, while regions on chromosome 2 have more modest evidence.

DNA Regions with Protective Genes. In cases where one sibling is dealing with alcoholism while the other is nonalcoholic, there is an evidence of a protective gene found in the region of chromosome 4. This means that variants of a gene or genes in this region may reduce risk of becoming alcohol dependent.

DNA Regions Related to Symptoms of Alcoholism. Signs and symptoms that are used to diagnose alcohol use disorder are very diverse, and range from biological symptoms to social symptoms. However, each individual who deals with AUD holds a unique set of symptoms. Therefore, a diagnose for AUD does not have a strict uniform phenotype. This fact complicates genetic analyses, but COGA researchers have created more defined phenotypes that are focused on the level of severity of alcoholism. These data provide evidence of DNA regions on chromosome 16 associated with higher risk for more severe drinking problems.

DNA Regions Associated with Co–Occurring Disorders. Many people diagnosed with depression also develop alcoholism. Depression and alcoholism are linked to a gene/or genes found in the region of chromosome 1.

DNA Regions Linked with Electrophysiological Measures. Reduced electrophysiological variables, such as EEGs (that measure brain activity) and ERPs (are brain waves elicited as a response to specific stimuli) seem to be a heritable phenotypes found in many cases of alcohol use disorder.

Candidate Genes. Some genes encode components of various brain chemicals such as dopamine and serotonin that allow communication among cells. If some of these routes of communications are disturbed, the person may be prone to using substances.

You can find more information on genes that put you at risk of becoming alcohol dependent here:

Main Findings

Just to clarify, there is still no clear evidence of what genes you need to have to be prone to becoming alcohol dependent. Specialists create theories that need to be more thoroughlt tested and elaborated upon. Additional work is required.

All theories and studies into the genetics of alcoholism share a common finding: alcohol changes in an addict’s brain activity.

Many substances affect the ‘reward circuit’ of the brain by releasing larger amounts of dopamine. This circuit regulates the ability to feel pleasure, and encourages a person to repeat the action that cause pleasure. If a person repeats the action over and over again, the brain starts to change, adopting the action as a normal and losing the ability to resist intense impulses (cravings).

And it is this change in brain function that makes it difficult to quit drinking. Here’s an explanation from the National Institute on Drug Abuse (NIDA) about how the brain responds to drugs like alcohol.


Genetics are only 50% responsible for the development of an alcohol use disorder.


Environment vs. DNA

Only 10% of people who consume alcoholwill go one to develop physical or mental dependency on alcohol.

So, how do genes affects alcohol addiction?

Genetics only make up half of the whole alcohol problem. Environment plays a huge role in becoming dependent. For instance, some people cannot deal with stress, and are unable to cope with hard relationships or work. So, as a coping mechanism they choose drinking. Also, people who are exposed to substances for longer time, are more likelyto become dependent. Moreover, a traumatic event may be the cause for one individual to turn to alcohol.

Some of the numerous environmental factors can include:

  • Attitudes and beliefs.
  • Bad parenting.
  • Culture background.
  • Financial status.
  • Life qualities.
  • Physical abuse.
  • Peer pressure.
  • School factors.
  • Sexual abuse.

… and many more.

The SAMHSA’s National Survey on Drug Use and Health report of 2016 estimated that 15.1 million people aged 12 or older had alcohol use disorder in the previous year. This means that 1 in 18 Americans had drinking problems. But, can we blame genetics for all these cases?

Of course not.

If you are genetically prone to developing alcohol use disorder, it doesn’t necessarily mean that you will become an alcoholic. As you begin to understand the genetics of addiction … you need to know that alcoholism is not an inevitability. Having genetic predisposition to alcohol problems simply means that you are at higher risk of a problem. And while drinking begins as a choice, many studies suggest that alcoholism is largely connected with an individual’s control.

So, the choice to raise a glass is yours. You make the decision to try alcohol, or not. Even though you may hold a high genetic risk of AUD, most people are first driven to try alcohol by a nonhereditary factor, which is usually environmental in nature. Here’s a diagram of the relationship between genes and environment that might provide you with a visual aid to understand the interplay:

Alcoholism Genetic Risk Factors

Many factors play a role in developing a drinking problem. These factors interact differently for different people. So, the same factors might lead to alcoholism in some, and not in others. The risk factors are divided into two categories:

External factors:

  • Age
  • Cultural norms
  • Education
  • Employment status
  • Environment
  • Family
  • Social norms
  • Religion

Internal factors:

  • Drinking history
  • Genetics
  • Personality
  • Personal choice
  • Psychological conditions

For example, findings published by the NIAAA show that children of alcoholics are about four times more likely to develop alcoholism than the general population. These children are also at high risk for many other behavioral and emotional problems. Genes are not the only factor in these cases, how alcoholic parents act and treat their children play a huge role in developing drinking problems. Some aspects that may increase the risk for alcoholism include:

  • An alcoholic parent is depressed or has other psychological issues.
  • Both parents drink alcohol and/or use other substances.
  • Conflicts because of alcohol use lead to aggression and violence in the family.
  • Parent’s alcohol use is severe.

To repeat, a combination of these risk factors may be the cause of alcohol use disorder for some, but not for others. This fact makes it difficult to predict who might become alcoholic, and who will not.

Avoiding a Problem

So, how can you protect yourself from a drinking problem? How can you avoid alcoholism if it runs in your family? The first thing you need to do in order to protect yourself is to learn your family history regarding alcoholism. Make a Family Map with an addiction counselor or other behavioral health professional…or you can learn how to make a family map here.

If you are among millions of people who have a parent, grandparent, or other close relative with drinking problems, there is a way to protect yourself by lowering these risks:

Avoid underage drinking. Underage drinking is illegal at the first place. Second, studies show that the risk of developing alcohol use disorder is higher among people who started drinking at early age.

Drink in moderation. Adults who choose to drink should drink in moderation. Not only because of the risk of alcoholism, but also because alcohol may cause many health problems.

Consult with a health care professional. Never hesitate to ask for help! Discuss your issues with professionals. They can help you find a suitable treatment or groups that can help you manage your alcohol problems.

The good news? Many children of alcoholics do not develop drinking problems. Awareness and action are key!

What’s Your Risk of Alcoholism?

Do you think that you may be at risk of developing alcohol use disorder? How can you be sure? The National Institute on Alcohol Abuse and Alcoholism outlines general guidelines.

For women, problem drinking is:

  • Drinking more that 1 standard drink daily.
  • Drinking more than 7 drinks weekly.
  • Drinking more than 3 drinks on any single day.

For men, problem drinking is::

  • Drinking more than 2 drinks daily.
  • Drinking more than 14 drinks weekly.
  • Drinking more than 4 drinks on any single day.

Moreover, there are also two ‘at-risk’ drinking patterns that can lead to alcohol use disorders:

1. Binge drinking – It is a drinking pattern that levels up the blood alcohol concentration (BAC) to 0.8 g/dl or above, which is usually happening after 4 drinks for women, and 5 drinks for men in a one drinking session of about 2 hours.

2. Heavy drinking is a binge drinking on 5 or more days in one month period.

Did you find yourself in some of these patterns?

Don’t wait until it’s too late, reach out for help!

Top 10 Alcohol and Genetics Facts

If drinking problems run in you family, don’t worry… It doesn’t mean that you will become addicted to alcohol. After all, even though you may have the ‘alcoholic gene’, alcoholism does not need to be your destiny. You are just at risk.

Below is a list of 10 facts about alcohol and genetics:

1. Genetics is about 50% responsible for developing alcohol use disorder.
2. One gene is not responsible for causing alcohol problems. A certain combination of hundreds of genes in individual’s DNA can increase the risk of developing alcoholism.
3. Having the ‘alcohol gene’ doesn’t mean that you will become an alcoholic.
4. Children with an alcoholic parent are four times more likely to develop alcohol use disorder.
5. Only 10% of people who drink become alcoholics.
6. Even though you may begenetically predisposed to alcoholism,your choice to try alcohol in the first place is usually triggered by envinronmental factors.
7. A combination of external and internal factors may lead to drinking problems.
8. Environmental factors play a huge role in developing alcoholism.
9. Drinking excessively over a long period of time puts you at higher risk of a drinking problem, even if you are not genetically predisposed to alcohol use disorder.
10. Scientists still haven’t identified which genes are responsible for increasing the risk of developing alcohol use disorder.

Reference sourses: NIAAA: Genetics of Alcohol Use Disorder
NIAAA: A Family History of Alcoholism
NIAAA: Collaborative Studies on Genetics of Alcoholism – Study
NCBI: Genetics and Alcoholism 
NCBI: Genetic factors influencing alcohol dependence
About the author
Lee Weber is a published author, medical writer, and woman in long-term recovery from addiction. Her latest book, The Definitive Guide to Addiction Interventions is set to reach university bookstores in early 2019.
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