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Updated November 28, 2022
The term ‘addiction’ is often referred to as ‘a family disease,’ but what does that actually mean? Is that a generalization or are some people more genetically predisposed to becoming addicted? The reality is, there are many factors that can cause someone to be vulnerable to addiction. No one is certain to develop an addiction to alcohol or drugs and no one is immune from all risk either. One of the factors that may predispose someone to addiction is heredity, and people whose family members have experienced addiction should familiarize themselves with the risks.
It’s an Important Question: Is There an Addiction Gene(s)?
Each year, addiction takes a financial toll on people in the U.S. to the tune of billions of dollars, but that isn’t the only fallout. Addiction to drugs and alcohol can impact all aspects of an individual’s life, such as their job, schooling, community standing, and family relationships. Because drug and alcohol addiction often plague more than one family member—and more than one generation—addiction is often referred to as a hereditary disease.
What Specific Genes Affect Addiction?
Is there an addictive gene? Not really; researchers can’t point to a single gene that causes addiction. The reality is considerably more complex. Addiction involves a wide range of biological processes; each one is influenced by a number of genes. That means that there are a number of genes that might increase your risk for addiction.
Let’s take a look at some addictive genes that researchers have identified.
ALDH2*2
Aldehyde dehydrogenase 2 (ALDH2) is a gene that affects how your body metabolizes alcohol. If you have the ALDH2*2 allele — a specific variation of the ALDH2 gene — your system may not be able to break down alcohol effectively. The liver converts alcohol to acetaldehyde, but it takes longer than usual to metabolize acetaldehyde into acetate.
The ALDH2*2 is commonly found in people of East Asian descent. Researchers estimate that 560 million East Asians carry the gene. It’s the reason for the so-called “Asian flush” that happens when someone with ALDH2*2 drinks alcohol. Since the liver can’t process it quickly, the acetaldehyde stays in your system for longer, causing hangover-like symptoms including a flushed face, a faster heart rate, low blood pressure, headaches and stomach upset.
Because of the uncomfortable symptoms associated with drinking, people with even one ALDH2*2 allele may be less likely to experience alcohol addiction. It’s important to note that the protective effect can be reduced over time if people push through their discomfort and continue to drink heavily.
ADH1B
Alcohol dehydrogenase 1B (ADH1B) is another gene that affects alcohol metabolism. The ADH1B*1 allele, which is the most common form of the gene, helps the liver process alcohol efficiently. People with this gene are less likely to have detectable levels of acetaldehyde buildup after drinking, which means they may not experience unpleasant effects.
One study found that men who have two ADH1B*1 alleles are two to four times more likely to become addicted to alcohol than men with other variations of the gene.
GABRA2
Gamma-aminobutyric acid type A receptor subunit alpha2 (GABRA2) is a gene that can affect how you react to alcohol. Specific variations of the gene have different responses. For example, people with the C allele may not experience strong sedative effects when they drink; this may cause them to drink more to achieve a similar effect. People with the G allele might experience the same sedative effect regardless of how much they drink, which can also prompt a higher consumption.
CHRM2
The cholinergic muscarinic receptor 2 (CHRM2) gene has been studied in connection to the prevalence of substance use disorders in families. Multiple studies have found that people with this gene have a higher risk of developing a substance abuse disorder, particularly during adolescence. The gene is often linked to a lack of inhibition, which may increase the risk. The effects are particularly strong in male children.
DRD2
The DRD2 gene is a dopamine receptor. Certain variations of this gene have been associated with cocaine addiction. Researchers hypothesize that because this gene affects how the brain processes reward and reinforcement, it may explain why some people become addicted to drugs and alcohol more easily than others. Keep in mind that this gene has been studied primarily in mice.
Per1 and Per2
Per1 and Per2 are part of the Period family of genes; they contribute to your body’s circadian clock, which affects the timing of bodily functions. These genes have also shown a correlation with substance abuse. Research suggests that certain variations affect how the body responds to drugs and alcohol.
The Per1 and Per2 research reinforces other studies that link circadian disruptions to addiction. That might mean that when people don’t have normal circadian rhythms, it alters the stability of their system. This can lead to substance abuse.
CHRNA2 and CHRNA5
The cholinergic receptor nicotinic alpha 2 (CHRNA2) gene influences the production of the nicotinic acetylcholine receptor (nAChR) protein. Depending on how the gene is expressed, it can affect how susceptible you are to cannabis use disorder.
The CHRNA5 gene seems to affect how your body reacts to nicotine. Studies show that the presence of this gene can reduce the negative effects of smoking, making carriers more prone to addiction and dependence.
MAOA
Certain polymorphisms of the monoamine oxidase A (MAOA) gene — typically, MAOA-LPR — are associated with higher rates of nicotine and alcohol addiction. Researchers believe this is partially due to the effect of MAOA on behavior and the response to external stimuli.
SLC6A4
The solute carrier family 6 member 4 (SLC6A4) gene affects serotonin transportation in the body. Different alleles of the gene can affect emotional arousal, mood disorders and addiction. The effects vary based on age, hormonal shifts, gender and ethnicity.
moody
In studies of flies, mutations of the moody gene caused a higher sensitivity to drugs including nicotine and cocaine. Flies with the same mutations also experienced a lower sensitivity to the effects of alcohol. Researchers surmised that these changes were rooted in the way the gene affects the blood-brain barrier.
OPRM1
The opioid receptor mu 1 (OPRM1) gene plays a role in a variety of addictions. The OPRM1 A118G polymorphism has been linked to opioid addiction. Researchers believe that it increases the positive reinforcement of opioids, which can make people more likely to become dependent. When it’s paired with certain ethnic and environmental factors, this variation has also been found to affect the response to treatment. In comparison to people with other variations, carriers often respond well to methadone treatments. This is because their bodies experience effects that are 2.3 times stronger than the effects in non-carriers.
CUL3, PDE4B and PTGER3
In a 2019 study funded by the National Institute on Drug Abuse (NIDA), researchers analyzed addiction-related behaviors with life events, diseases and health. Then, they correlated the results with the genes that are involved in substance abuse. This process showed that more than 400 genomic locations can affect how you use nicotine and alcohol. Within those locations, researchers identified at least 566 variants.
These results suggest that the genetic factors that affect addiction are extremely complex. However, researchers did find three genes that were common in all the identified nicotine and alcohol phenotypes: CUL3, PDE4B and PTGER3.
Is Addiction to Drugs or Alcohol Hereditary? The Biological Factors
According to the American Psychological Association, genetic factors can make up “at least half of a person’s susceptibility to drug addiction.” Researchers are also beginning to better understand the biological factors that can make addiction inheritable from one generation to another. For instance, evidence suggests that individuals who have fewer D2 dopamine receptors are more likely to become addicted than people with many of these receptors; and there is hope within the scientific community that one day a certain dopamine receptor might be used to identify whether someone is susceptible to drug or alcohol addiction.
Such breakthroughs are promising. They mean that brain imaging may one day be used as a preventative tool, helping people understand their genetic risk factors to things like alcoholism and opioid addiction.
However, while genetic factors can render a person more susceptible to the disorder than someone else may be, they do not categorically determine whether a person will become addicted or not. Often, other factors—namely, environmental factors—play a substantial role in the development of addictions.
Why Genes and Biology Are Only Half of It
The fact remains, even the most genetically susceptible person won’t develop an addiction if they refrain from using alcohol or drugs altogether. It’s clear that a variety of factors are at play when it comes to the development of addiction. That’s why addiction is often referred to as a “multi-type” disease, because it involves physical, psychological, and behavioral factors.
In recent years, the medical community has dubbed the term “addiction” a disease. It can be governed by genes in the same way that other diseases can be. For instance, heart disease can be hereditary.
However, even people without a genetic susceptibility can develop either addiction or heart disease as a result of their behaviors. A person who abuses alcohol routinely can easily become addicted to it. A person who eats a high-cholesterol diet can develop heart disease. So, addiction, in a very real sense, is a complex condition that must be unraveled and evaluated during the treatment process.
It’s also worth noting that addiction is different from many diseases like heart disease because it involves both physical and mental components. Yes, a person can become physically addicted to a drug or alcohol to a point where they become violently ill without it.
On the other hand, drugs and alcohol do change the chemistry of the brain. These changes result in the powerful psychological compulsions that individuals experience once they become addicted to drugs or alcohol. It’s why people seem unable to stop using in spite of the negative effects they suffer.
What Environmental Factors Make Someone Susceptible to Addiction?
For researchers, it’s often a combination of factors they identify in people suffering from addiction. For instance, a person born to a parent who has an alcohol addiction may be genetically predisposed to the condition as well.
However, simply being present in a home where a parent or guardian abuses alcohol or drugs is also a risk factor for addiction development. Why? Because children often mimic their elders. If a person drinks to quell their anger or stress, kids see and learn that behavior.
Family members’ habits aren’t the only environmental factors associated with addiction development. A person’s peer group and socio-economic status are also strong factors. Although addiction affects people in all socio-economic groups, those individuals living in poverty are at the greatest risk for developing an addiction.
A person’s social or peer group can also have a strong impact. Being in close proximity to others abusing alcohol or drugs increases the likelihood of use and, ultimately, abuse.
The Link Between Addictions
Studies have shown that addiction is 50 percent due to genetic predisposition and 50 percent due to poor coping skills. This statistic might be alarming, but it’s important to remember that everyone can become addicted from a genetic standpoint; it’s just that some might be a bit more susceptible, genetically speaking, than others.
To be specific, there is no one “addiction gene,” but rather a genetic makeup that makes us more or less likely to suffer addiction given our actions (i.e drinking at a young age, drinking to drown negative emotions, trying powerful drugs like heroin). Genetics only account for half the susceptibility to drug or alcohol addiction. The other half is often related to environmental factors and poor coping skills that leave a person more vulnerable.
Are Children of Addicts at Heightened Risk?
One study revealed that children of addicts are eight times more likely to develop an addiction than others. The study observed 231 individuals who had an addiction and compared them to 61 people who did not have an addiction. Following that, it looked at first-degree relatives of the individuals and determined that people addicted to a substance are eight times as likely to produce children who will become addicted.
But how can this generational transmission happen? Is it a gene in the brain? Does it predispose children to be more likely, genetically? Not exclusively, but it is worth examining.
Researchers have not identified the quantifiable characteristic that is being passed on to the next generation; they just know that people who suffer from addiction tend to be related to other people who suffer from the same disease. The answer may lie in the other 50 percent: those poor coping skills.
Children with addicted parents are statistically more likely to lead unhealthy lifestyles and have trouble coping with things like negative emotions or stress. These coping skills affect their future and their prospects of become addicted. Additionally, if a mother is using while pregnant, there is an even greater chance that the child will become addicted to drugs or alcohol.
What To Do?
Anyone concerned about developing an addiction or concerned about their children should take time to learn their family history. If relatives suffer from addiction, there’s some likelihood that a genetic predisposition could run in the family.
A robust defense against this predisposition is to avoid alcohol and drug use or be mindful about one’s drinking habits. Developing healthy ways to cope with stress or negative feelings can prevent someone from using alcohol or drugs to cope.
Getting Help
If you or a loved one are struggling with an addiction, you owe it to yourself and those around you to seek treatment. FHE Health can provide a detailed evaluation and recommend next steps. Our counselors are available 24/7 to answer questions.
Nobody is purely the sum of their genes. Take your life back today.
