In the United States, it is legal for someone who is 21 or older to purchase and drink alcohol. Most adults in this country drink ocassionally, with meals, to celebrate holidays or accomplishments, or socially with friends.
According to information gathered from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) data, about 30 percent of American adults do not drink alcohol at all, and another 30 percent consume about one drink per week. The top 10 percent of American adults, however, consume 74 drinks per week on average, shaking out to about 10 drinks per day. This pattern of heavy, excessive drinking indicates potential problems with alcohol use disorder (AUD), the clinical term for alcoholism.
The National Institute on Alcohol Abuse and Alcoholism (NIAAA) reports that, as of 2015, 86.4 percent of people in the U.S., ages 18 and older, reported having at least one alcoholic beverage in their lifetime, and 56 percent of this group reported drinking at least once in the past month. In that same group, 26.9 percent reported that they binge drink at least once in the past month, and 7 percent reported heavy drinking in the past month.
Binge drinking is the practice of having four or more servings of alcohol in a two-hour period while heavy drinking is defined as having more than seven alcoholic beverages in a week, or about one to two beverages per day. Neither binge nor heavy drinking are alcoholism specifically, but they can indicate a potential AUD, especially when a person who drinks heavily also regularly binge drinks. An estimated 15.1 million adults, and 623,000 adolescents ages 12 to 17, struggle with AUD.
Several factors influence whether you might develop alcoholism. Your family history and your current environment are two major factors, but another is genetics. If you have certain genes that are associated with AUD, you may struggle with safe alcohol consumption.
However, having the genes for AUD does not automatically mean you will develop alcoholism. Many people who are at risk for this condition have successfully maintained moderate drinking levels or don’t drink at all. It is important to understand your risks, so that you can keep you and your family healthy.
The reason so many people enjoy alcohol’s effects, even once in a while, is because the chemical influences the gamma-aminobutyric acid (GABA) neurotransmitter. Alcohol indirectly stimulates the release of this neurotransmitter, which is involved in managing how rapidly neurons fire. Without enough GABA in the brain, you may feel anxious, struggle with insomnia, struggle with panic attacks, or even, at its most extreme, have a seizure disorder like epilepsy. By suppressing neuron spasms, GABA allows relaxation and calmness. This intoxicant can lead to a feeling of well-being, sleepiness, or satisfaction. Alcohol mimics this effect in the brain by binding to the GABA receptors.
At the same time, alcohol inhibits glutamate, one of the major excitatory neurotransmitters that induces more relaxation. These two effects together can create a pleasant sensation that triggers the brain’s reward system, releasing dopamine and serotonin. Many people who experience this confluence of satisfying neurotransmitters want to recreate the feeling. For some, this can lead to compulsive behaviors and addiction.
The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) defines alcohol use disorder by these 11 criteria.
If you experience two of these 11 criteria for more than a year, the DSM-5 defines that as a mild AUD. Four to five of these symptoms is considered moderate AUD, and six or more is severe AUD.
You are not guaranteed to develop an alcohol use disorder just because you have some genetic markers, but the condition is more likely to develop if you begin drinking. Genetics influence how your brain interacts with alcohol. If you experience more pleasant effects from drinking, you are more likely to continue drinking despite negative consequences.
Research into the genetics of alcoholism is a new field, but scientists are finding new ways to understand how AUD becomes a problem, so they can approach treatment and prevention with better evidence.
Generally, individual health is a combination of genetics and environmental influences on gene expression. For example, if you have genetic risks for high blood pressure, your diet, exercise routine, and daily stress level can all influence whether you develop this condition or not. You also can use diet and exercise changes, along with methods to manage your stress levels, to reduce your risk of developing high blood pressure if you know you have these risk factors.
Because the brain evolved to stimulate the reward system in certain conditions, most of us are at least a little predisposed to abusing substances. Eating sugary foods, drinking caffeine, or consuming drugs can all trigger the reward system and lead to compulsive behaviors.
Specific genes, according to recent research, make up about 50 percent of a person’s risk for developing addiction, including AUD. A family history of addiction or mental illness can influence whether these genes are expressed or not. The stress of being around an unpredictable person struggle with a mental illness or addiction can trigger AUD as a reaction to stress management, for example, or it can cause the person to react the other way and avoid alcohol or intoxicating substances altogether. Trying drugs or alcohol can begin rewiring the brain faster in people who have a genetic predisposition to this condition, so exposure to these substances in your environment can lead to addiction.
Research published in 2013 began identifying potential genetic markers for alcohol use disorder. Genes ADH1B and ALDH2 are associated with alcohol metabolism and appear to have the strongest links to an increased risk of AUD. However, some expressions of these genes protect against AUD by making alcohol metabolism uncomfortable.
Genes GABRA2, CHRM2, KCNJ6, and AUTS2 also have been linked to this addiction because they influence how rapidly the brain becomes dependent on the presence of alcohol. With these genes present, being exposed to alcohol increases the risk that you will develop cravings for the beverage, but again, it does not guarantee that you will develop alcohol dependence or addiction.
A 2016 study on rats with alcohol dependence found that alcoholism is not related to one gene or even one small set of genes. There are several influencing factors that create a network, both in DNA and in your environment.
A report published through the National Institute on Drug Abuse (NIDA) agrees with this assessment of AUD’s complexity. Genes with strong effects are the exception, not the rule. That report backs up studies that alcohol metabolism has the strongest influence. When the ADH1B gene is highly active, breaking alcohol into acetaldehyde (though there is a very slow breakdown of that chemical into acetate), the individual is less likely to drink because the effects of intoxication will be uncomfortable.
Other influences on the development of alcoholism are the genes responsible for the GABA system. A specific gene called GABRA2 can express in a way that makes one more susceptible to the positive, euphoric effects of alcohol by managing GABA neurotransmitters differently. This can lead to alcohol abuse because the person wants to keep experiencing the positive effects of alcohol and may experience worse hangovers or cravings without alcohol.
Learning more about genetic influences involved in AUD can help clinicians improve treatment approaches. Strategies, from prevention to long-term rehabilitation, all improve with greater understanding of the genetic underpinnings of alcohol abuse.
NIAAA reports that there are several approaches to treating people at risk of AUD.
As the medical community develops a greater understanding of alcoholism, there are better preventative strategies and treatment options for people who struggle with this addiction. Understanding genetic risks is part of this process. It can help you learn if you are at risk and how you can get help, both to avoid alcohol addiction and to get the best treatment tailored for you if you do develop AUD.
Think You Drink a Lot? This Chart Will Tell You. (September 25, 2014). The Washington Post. from https://www.washingtonpost.com/news/wonk/wp/2014/09/25/think-you-drink-a-lot-this-chart-will-tell-you/?utm_term=.ee3b3ec1e127
Alcohol Facts and Statistics. (June 2017). National Institute on Alcohol Abuse and Alcoholism. from https://www.niaaa.nih.gov/alcohol-health/overview-alcohol-consumption/alcohol-facts-and-statistics
The Effects of Alcohol on the Brain. (February 25, 2002). Scripps Research Institute. from https://www.scripps.edu/newsandviews/e_20020225/koob2.html
Alcohol Use Disorder. National Institute on Alcohol Abuse and Alcoholism. from https://www.niaaa.nih.gov/alcohol-health/overview-alcohol-consumption/alcohol-use-disorders
Alcohol Use Disorder. (July 19, 2018). Psychology Today. from https://www.psychologytoday.com/us/conditions/alcohol-use-disorder
Family History and Genetics. (April 25, 2015). National Council on Alcoholism and Drug Dependence. from https://www.ncadd.org/about-addiction/family-history-and-genetics
Genetics and Alcoholism. (May 28, 2013). Nature Reviews Gastroenterology & Hepatology. from https://www.nature.com/articles/nrgastro.2013.86
Drink-Seeking Rats Provide Sobering Look Into Genetics of Alcoholism. (August 4, 2016). Purdue University, ScienceDaily. from https://www.sciencedaily.com/releases/2016/08/160804152727.htm
Genetics of Alcoholism. (2011). Howard J. Edenberg, Indiana University School of Medicine. National Institute on Drug Abuse. from http://126.96.36.199/sites/default/files/edenberg_speaker_formt.pdf
Alcohol Alert: The Genetics of Alcoholism. (2012). National Institute on Alcohol Abuse and Alcoholism. from https://pubs.niaaa.nih.gov/publications/AA84/AA84.pdf
Medication for the Treatment of Alcohol Use Disorder: A Brief Guide. (2015). National Institute on Alcohol Abuse and Alcoholism. from https://store.samhsa.gov/sites/default/files/d7/priv/sma15-4907.pdf
Intervention: Help a Loved One Overcome Addiction. (July 20, 2017). Mayo Clinic. from https://www.mayoclinic.org/diseases-conditions/mental-illness/in-depth/intervention/ART-20047451?p=1
Treating Alcohol Withdrawal With Benzodiazepines – Safe if Mindful. (May 27, 2012). Psychology Today. from https://www.psychologytoday.com/us/blog/all-about-addiction/201205/treating-alcohol-withdrawal-benzodiazepines-safe-if-mindful