Hugo Bellen, a geneticist at Baylor College of Medicine in Houston, Texas, said the study «lays the foundation for a genetic approach to dissecting the acute, and possibly the chronic, effects» of alcohol in people. A study in Sweden followed alcohol use in twins who were adopted as children and reared apart. The incidence of alcoholism was slightly higher among people who were exposed to alcoholism only through their adoptive families. However, it was dramatically higher among the twins whose biological fathers were alcoholics, regardless of the presence of alcoholism in their adoptive families. The causes of AUD are complex and can involve a variety of factors, including early exposure to alcohol use, peer group pressure, and living with other mental health conditions. Genetic disorders are diagnosable conditions directly caused by genetic mutations that are inherited or occur later in life from environmental exposure.
Having a close family relative, such as a parent, can account for up to 60% of your risk of developing AUD. The Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR), a clinical diagnostic guidebook, indicates that AUD often runs in families at a rate of 3–4 times higher compared with the general population. According to the 2021 National Survey on Drug Use and alcohol use disorder and timeline of alcohol withdrawal symptoms Health, AUD affects approximately 29.5 million people in the United States. More than 800,000 of the people affected are children between the ages of 12 and 17 years. Alcohol use disorder (AUD) is a diagnosis once referred to as “alcoholism.” It’s a condition characterized by patterns of excessive alcohol misuse despite negative consequences and major distress in important areas of daily function.
- However, it was dramatically higher among the twins whose biological fathers were alcoholics, regardless of the presence of alcoholism in their adoptive families.
- Environmental factors also account for the risk of alcohol and drug abuse.2 Scientists are learning more about how epigenetics affect our risk of developing AUD.
- As we’ve learned more about how genes play a role in our health, researchers have discovered that different factors can affect the expression of our genes.
- Like many other complex traits, alcoholism appears to be clinically and etiologicaly hetrogenous[13].
- Scientists are learning more and more about how epigenetics can affect our risk for developing AUD.
But substance abuse isn’t determined only by the genes you inherit from your parents. AUD isn’t directly caused by genetics, but genetics may predispose you to developing AUD later in life. This risk is considered hereditary and may be passed down to you if you have a family history of AUD.
Over the past two decades, several genesunderlying susceptibility have been identified. Extensive study of the alcoholmetabolizing genes has demonstrated their important role in disease risk. Additionalgenes have been identified that have expanded our understanding of the genes andpathways involved; however, the number of findings to date is modest.
Some protective factors, such as natural optimism, may remain fixed over time. Other factors, such as friend groups and level of financial security, may be subject to change. That doesn’t mean you’ll absolutely develop AUD if you have a family member living with the condition. You may have a higher genetic predisposition, but the underlying causes of AUD are multifaceted and complex.
Alcohol is metabolized primarily in the liver, although thereis some metabolism in the upper GI tract and stomach. The first step in ethanolmetabolism is oxidation to acetaldehyde, catalyzed primarily by ADHs; there are 7closely related ADHs clustered on chromosome 4 (reviewed in20). The second step is metabolism of theacetaldehyde to acetate by ALDHs; again, there are dangers of mixing adderall and alcohol many aldehyde dehydrogenases,among which ALDH2 has the largest impact on alcohol consumption20. In the study of complex disorders, it has become apparent that quitelarge sample sizes are critical if robust association results are to beidentified which replicate across studies. Unfortunately, studies of alcoholdependence have not yet attained these sample sizes.
In 1990, Blum et al. proposed an association between the A1 allele of the DRD2 gene and alcoholism. The DRD2 gene was the first candidate gene that showed promise of an association with alcoholism. Your genetic risk refers to the likelihood that specific genes or genetic variants passed down to you will lead to a particular condition. What this means for family members of alcoholics is that you are not necessarily going to misuse alcohol yourself. Factors like your environment and ability to handle situations triggering dependency are just as important as genetics. These are things that we can remain mindful of as we continue to develop an understanding of alcoholism on a personal basis.
Genetics of alcohol-associated diseases
Abundant evidence indicates thatalcoholism is a complex genetic disease, with variations in a large number ofgenes affecting risk. Some of these genes have been identified, including twogenes of alcohol metabolism, ADH1B and ALDH2,that have the strongest known affects on risk for alcoholism. Studies arerevealing other genes in which variants impact risk for alcoholism or relatedtraits, including GABRA2, CHRM2,KCNJ6, and AUTS2. As larger samples areassembled and more variants analyzed, a much fuller picture of the many genesand pathways that impact risk will be discovered. There are several other genes that have been shown to contribute to the riskof alcohol dependence as well as key endophenotypes. The earliest genes weretypically identified as a result of family-based analyses.
Because the diagnosis of an AUD requires the presence of a set ofsymptoms from a checklist, there are many different ways one could meet thecriteria. There are 35 different ways one could pick 3 criteria from 7 (DSM-IValcohol dependence) and 330 ways to pick 4 from 11 (DSM-5 severe AUD). The clinicalheterogeneity likely reflects the genetic heterogeneity of the disease. Thedifficulties of genetic studies are compounded by environmental heterogeneity inaccess to alcohol and social norms related to drinking. They may increase the overall risk by increasing drinking, orreduce risk by reducing drinking. Some alleles that reduce heavy drinking can,nevertheless, increase risk for disease in the subset of individuals who drinkheavily despite having them.
Functional significance of GWAS variants
They seem to lose fewer inhibitions and tolerate alcohol for longer before they pass out. Substance abuse treatment usually involves a comprehensive approach that combines medical and psychosocial interventions. The environment in which people live and work heavily affects their attitudes and drinking behaviors. Just as risk factors increase your chance of experiencing a condition, protective factors lower your risk.
Genetics aren’t the only way your parents or caregivers can influence AUD risk. Living in a household where you’re regularly exposed to parental alcohol use can also increase your chances of AUD, regardless of your genetic predisposition. «These genes are for risk, not for destiny,» stressed Dr. Enoch Gordis, director of the National Institute drug addiction blog on Alcohol Abuse and Alcoholism. He added that the research could help in identifying youngsters at risk of becoming alcoholics and could lead to early prevention efforts. Witnessing parents abusing alcohol and experiencing the linked disruptions can increase the likelihood of developing problematic drinking patterns later in life.
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Environmental factors also account for the risk of alcohol and drug abuse.2 Scientists are learning more about how epigenetics affect our risk of developing AUD. But while genetics influence our likelihood of developing alcoholism, it’s more complex. A review of studies from 2020, which looked at a genome-wide analysis of more than 435,000 people, found 29 different genetic variants that increased the risk of problematic drinking. Family, twin, and adoption studies have shown that alcoholism definitely has a genetic component.
What are the protective factors for AUD?
While many studies have been done, and experts agree that there is a hereditary connection, genetics is not the only factor, and we don’t quite know the full impact it has on alcoholism. The classification of an alcohol use disorder as a disease has significant implications for prevention and treatment. It emphasizes the need for medical and psychological interventions rather than viewing it solely as a moral or personal failing. They are essential in influencing the brain’s function and response to addictive substances like alcohol.
In most cases, studiesrecruited families having multiple members with alcohol dependence; such familiesare likely to segregate variants that affect the risk of alcohol dependence. Themost common initial approach was linkage analysis, in which markers throughout thegenome were measured to identify chromosomal regions that appeared to segregate withdisease across many families. The drawback to this approach isthat linkage studies find broad regions of the genome, often containing manyhundreds of genes. In many cases, the initial linkage studies were followed by moredetailed genetic analyses employing single nucleotide polymorphisms (SNPs) that weregenotyped at high density across the linked regions. Some of the genes identifiedthrough this approach have been replicated across a number of studies and appear tobe robust genetic findings. Family studies have consistently demonstrated that there is a substantialgenetic contribution to alcohol dependence.
