Genes play a vital role in the development of any addiction, but they are not the only factor. To differing degrees, genes work in concert with outside factors to influence a person’s response to substances along with his behavior.
How Genes Influence Disease Development
The human body contains an estimated 20,000 to 21,000 genes. The genetic information enclosed in each human cell influences almost everything from the way a person walks and talks to how he responds to the outside world. Some genes play a role in addiction, influencing the way a person responds to specific chemicals and the likelihood he will develop a dependence on certain drugs with even casual use.
While greater understanding about genes may eventually lead to treatments that end addiction, there are serious limitations in the current understanding of addiction and genetics. Many studies suggest a link between genes and substance use exists, but more work must be done before experts know enough to take meaningful action with their knowledge.
With the completion of the Human Genome Project (HGP) in 2003, researchers had the base materials to conduct even more vigorous research into the connection between genes and addiction. The HGP allowed researchers to identify all of the genes making up human DNA, and transfer the results to the public sector for researchers. For the first time, scientists could access the sequences of human DNA’s 3 billion chemical base pairs, and develop studies to compare a sample of one type of DNA with the types sequenced as part of the HGP.
Researchers experiment with a variety of factors as they study addiction and genetics, but they commonly look for groups of people who have strong family histories of addiction. Families with several documented cases of alcoholism, for example, or families with several members who have opiate addictions make ideal test cases. Researchers then request blood samples from all family members, whether they are addicted or not, and then analyze the samples looking for stretches of DNA similar in people who are addicted, but dissimilar from people who are not addicted.
They conclude the research by going back to the samples and looking for mutations in the genes within the addicted families.
While the current research is promising, there are limitations. For example, some people may share the same genetic markers with their addicted family members and still not develop an addiction. Additionally, some people may have no addiction hallmarks, come from families with no history of addiction and ultimately develop an addiction. These examples skew overall results. In addition, with billions of base pairs of DNA in play, it’s difficult for researchers to pinpoint the multiple genes affecting any one condition. Finding the genes most likely to impact addiction could take years or even decades of patient, diligent research.
Research on other conditions influenced by genetics sheds more light on the issue. For example, the interaction between a specific set of mutations associated with breast cancer in women shows the complexity of finding a smoking gun for any disease.
About 12 percent of women who do not have the mutations associated with breast cancer still develop breast cancer, compared with up to 60 percent of the women who do have the mutations. Even when researchers find a specific genetic marker for a condition, it doesn’t show a definitive link between the gene and the disease. It’s clear other factors also influence the development of disease.
DNA, Genetics Factors and Addiction
According to the National Institute on Drug Abuse (NIDA), genetic information accounts for about half of a person’s vulnerability for addiction.
- Friends, social networks
- Age a person begins using drugs or alcohol
- Neighborhood where a person lives
- Availability of drugs and alcohol
- Presence of mental health issues
- Person’s gender
Current research indicates genes are a bit like suggestions for cells to follow. Certain genes may represent a vulnerability to addiction, but they do not indicate certainty. Babies aren’t born doomed to become addicts in later life. Any gene, whether it’s associated with cancer, heart disease, addiction or some other health issue, must interact with the environment in some way.
There must be a trigger that turns the gene on and allows the process to begin. Without the trigger, the gene may remain dormant. Furthermore, some people develop addiction through lifestyle alone, without the involvement of currently known genes.4
While addiction genes need a push from the environment to turn on, several studies suggest specific genes in the human body heavily influence addiction. Given a tiny push, these genes spring into action and promote addictive behaviors.
Studies performed on monkeys offer significant information about the relationship between genes and substance use. Because of years of research on monkeys, researchers know a meaningful amount about monkey genes and how specific genes influence a variety of health conditions. In one interesting study reported by the National Institutes of Health, monkeys with a specific adaptation to a gene that controls serotonin drink more alcohol than monkeys without the adaptation. When the monkeys with the adaptation are separated from their mothers and raised by other monkeys, they drink even more.
Studies on human subjects provide even more information about the link between genes and addiction. A study funded by the NIDA examined 352 pairs of identical male twins and 255 pairs of fraternal male twins. The two pairs answered questions about how marijuana made them feel, and how much they enjoyed it. The responses by the identical twins (who share all of the same genes) were much more alike than the responses given by fraternal twins (who share only about half of their genes). While this study did not identify a specific gene involved in marijuana enjoyment, it did offer evidence to indicate some genes are involved in enjoying the sensation of smoking marijuana. For example, enjoying a drug leads the user to take it again, while disliking itprevents further use.
Some studies on humans rely on the habits family members share. Since families share genes, these studies may indicate a genetic component, even though the individual genes involved are not known. In one such study, the National Institute on Alcohol Abuse and Alcoholism reports that children of alcoholics are between four and 10 times more likely to become alcoholics themselves, as compared to people who have no close relatives who are alcoholics. They’re also more likely to begin drinking prior to age 27, and they tend to progress through the stages of alcoholism more quickly than people who do not have alcoholic relatives. Multiple studies seem to suggest a link between genes and alcoholism, and this is a field researchers continue to study closely.
A similar study illustrates another possible link between drug addiction and genetics. The study found people who were born to parents with addictions, but who were raised in adoptive families, were more likely to abuse substances than people who were raised in the same adoptive environments but were born to non-substance-abusing parents. Again, this study cannot identify which genes made the people susceptible.
Also, there are other issues to consider. People who grow up in adoptive families may feel alienated or isolated, if they feel judged or left out because they’re not genetically related to their adoptive family. Such isolation could lead to risky decisions and drug experimentation, or it could lead to depression and substance use. More research is needed to make stronger conclusions.
Researchers will continue experiments with rats, mice and monkeys, making small changes to their DNA strands and observing how they respond to opportunities to drink or use drugs. As the body of research grows, they make more reasonable assumptions about how genes work in humans. The ultimate goal is to develop therapies to help people recover from addictions.
Living in the Moment
While research is ongoing, and many questions remain, it’s important to know many current addiction treatments offer real hope. Although there is no way to correct faulty genes, and no tests that indicate a vulnerability to addiction, there are many scientifically researched treatments that alleviate the behavioral symptoms of addiction along with several medications that treat alcohol use, opiate use and tobacco use.
While there is significant potential for genetic therapies in the future, there are several strategies people should try in the present, including the following:
- People with a family history of drug or alcohol abuse should avoid addictive substances. It’s best not to risk the combination of genes and environment.
- Parents with a history of substance abuse should encourage their children to avoid experimenting with drugs or alcohol during adolescence. The teen brain is more vulnerable to addiction, and it’s crucial to avoid experimentation that sets adolescents up for more severe addictions and a lifetime of risk.
- People with a family history should get early interventions for addiction instead of dealing with the issue alone. Getting help early, and sticking with treatment, is the best way to keep a lapse from becoming a major break.
- Families with addiction histories should maintain open lines of communication about addiction and experimentation. Parents and children who discuss the topic openly and honestly can support one another effectively.
Fortunately, there are addiction treatments that help people at any point of their lives. Psychological therapies address the behavioral and cognitive sides of addiction and ongoing support gives people the ability to fight temptation even when they struggle with stress or unexpected situations.
How We Can Help
At Skywood Recovery, we specialize in providing effective addiction treatments rooted in sound scientific principles. We keep abreast of the research, so we can ensure we provide our patients with the best care possible. If you’re struggling with an addiction, or you know someone needs help, please contact us and find out more about the treatments we offer.
Ezkurdia, I., Juan, D., Rodriguez, J. M., Frankish, A., Diekhans, M., Harrow, J., et al. (2014). Multiple evidence strands suggest that there may be as few as 19 000 human protein-coding genes. Human Molecular Genetics. Retrieved Jan. 4, 2017 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4204768/.
Bevilacqua, L., & Goldman, D. (2009). Genes and Addictions. Clinical Pharmacology and Therapeutics. Retrieved Jan. 4, 2017 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2715956/.
 Human Genome Project. (2016). Human Genome Project Information Archive. Retrieved Jan. 4, 2017 from http://web.ornl.gov/sci/techresources/Human_Genome/index.shtml.
 University of Utah: Genetic Science Learning Center. (2013). Genes and Addiction. Retrieved Jan. 4, 2017, from http://learn.genetics.utah.edu/content/addiction/genes.
 National Institute on Drug Abuse. (2016). Genetics and Epigenetics of Addiction. Retrieved Jan. 4, 2017 from https://www.drugabuse.gov/publications/drugfacts/genetics-epigenetics-addiction.
 National Cancer Institute. (2015). BRCA1 and BRCA2: Cancer Risk and Genetic Testing. Retrieved Jan. 4, 2017 from https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet.
 National Institute on Drug Abuse. (2014). Drug Abuse and Addiction. Drugs, Brains, and Behavior: The Science of Addiction. Retrieved Jan. 4, 2017 from https://www.drugabuse.gov/publications/drugs-brains-behavior-science-addiction/drug-abuse-addiction.
 National Institutes on Health. (2013). Genes, Behavior, the Environment, and Health. Retrieved Jan. 5, 2017 from https://report.nih.gov/NIHfactsheets/ViewFactSheet.aspx?csid=41.
 Wyman, June R. (1997). Promising Advances Toward Understanding the Genetic Roots of Addiction. NIDA Notes. Retrieved Jan. 4, 2017 from https://archives.drugabuse.gov/NIDA_Notes/NNVol12N4/Promising.html.
 National Institute on Alcohol Abuse and Alcoholism. (2006). Why Do Adolescents Drink, What Are the Risks, and How Can Underage Drinking Be Prevented? Alcohol Alert. Retrieved Jan. 4, 2017 from https://pubs.niaaa.nih.gov/publications/AA67/AA67.htm.
 Cadoret, R.J.; O’Gorman, T; Troughton, E.; Heywood, E. (1986). An adoption study of genetic and environmental factors in drug abuse. Archives of General Psychiatry. Retrieved Jan. 4, 2017 from https://www.ncbi.nlm.nih.gov/pubmed/3778110.
 National Institute on Drug Abuse. (2012). Evidence-Based Approaches to Drug Addiction Treatment. Principles of Drug Addiction Treatment: A Research-Based Guide (Third Edition). Retrieved Jan. 4, 2017 from https://www.drugabuse.gov/publications/principles-drug-addiction-treatment-research-based-guide-third-edition/evidence-based-approaches-to-drug-addiction-treatment.