Addiction is a complex mental health issue thought to develop as a result of various influencing factors. The general character and progression of individual cases of addiction are likely to be unique. It is perhaps unsurprising, then, that the path to long-term recovery from addiction may also be somewhat different for everyone, though many will embark on recovery with the help of a similar set of therapeutic elements, including detox and withdrawal management, medication, behavioral interventions, relapse prevention skills training, and a continued focus on aftercare efforts.
Our genetic makeup plays a decided role in both protecting from and increasing our risk of certain addictions. Genes may not only influence our likelihood to become addicted to a substance, but also of the severity of that addiction. Our understanding of the genetic impact on addiction vulnerability will undoubtedly have significant implications for modern drug and alcohol addiction treatment as well as the prevention of addiction in the first place.
For instance, our genes may influence the way we respond to certain forms of treatment, including medications. Research in the field is ongoing, but the information we learn from such studies will likely become an increasingly influential aspect of personalized treatment design—one with the potential to make a huge positive difference to in terms of healthcare costs, patient outcomes, and the overall well-being of those recovering from addiction.1
Understanding Genetics and Addiction
To better understand the promise of genetics research on addiction treatment, it helps to start with some general understanding of what genes are.
What are Genes?
Genes are comprised of an ordered sequence of deoxyribonucleic acids, or DNA, and serve as the most basic and fundamental units of heredity. Estimates point to there being between 20,000 and 25,000 genes in the human genome.2 A subset of any organism’s genetic material serves as the molecular blueprints for protein synthesis which, in turn, helps determine the variably-expressed characteristics of all biological life-forms.
Such points of expression, of course, include certain observable characteristics such as height or eye color, but others might play a role in more covert physiological processes and, in doing so, influence the development of various medical conditions. For example, mutations to certain genes are associated with conditions such as cystic fibrosis, muscular dystrophy, and Tay-Sachs disease or may impart a tendency for a person to develop breast or ovarian cancers.3,4
In many cases, though the presence of certain genetic variants may influence whether you’re at risk for a medical condition, they don’t mean you absolutely will develop that condition.
What is Addiction?
The American Society of Addiction Medicine defines addiction as a chronic medical condition that involves a complex interaction of brain circuitry, genetics, and life experiences. People with addictions exhibit compulsive substance use behavior and often continue to drink or use drugs despite the harmful consequences of such behavior.5
Many who struggle with addiction may find themselves withdrawing from multiple areas of their everyday lives—for example, they may begin to participate less with social, occupational, or previously-enjoyed recreational activities. Additionally, they may continue their problematic substance use despite the negative impact it is having socially, interpersonally, and on their overall health.6
Though it is a more significant issue with specific substances, physiological dependence is associated with many types of addiction. The presence of physiological dependence is itself one of several criteria used to make a substance use disorder diagnosis. In those who have already developed some degree of dependence, abruptly quitting or slowing continued use of a substance can result in the onset of withdrawal. Acute substance withdrawal can be physically uncomfortable, difficult to endure and, if not medically managed, life-threatening in some instances (e.g., severe alcohol withdrawal). The fear of an impending withdrawal syndrome could potentially lead to delayed treatment seeking. Furthermore, unmanaged withdrawal may compel relapse in some cases which, of course, will complicate an individual’s addiction recovery.7
The Impact of Genetics on Addiction
Studies of the interplay between genetics and addiction development are ongoing. As mentioned earlier, we know it’s a complex relationship and unlikely that any single gene governs addiction development (though evidence suggests that genetic factors may account for 40-60% of our vulnerability to addiction—a concept known as heritability).7,8
A 2008 review paper published by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) indicates that genetic factors may contribute to as much as 50 to 60 percent of the variance in risk for developing alcohol dependence; while this percentage underscores the significance of genetic influences, it also suggests that several nongenetic factors play a hand in conferred addiction risks.9
More specifically, there is also evidence that genetic differences in neuroendocrine functionality, such as that regulated by the hypothalamic-pituitary-adrenal axis, as well inherited variations such as dopaminergic receptor number and activity level may be associated with increased SUD risks.8
Research into this field is far from complete. While we still have a lot to learn about how genetics and addiction work, studies support the important role that genes play in addiction development as well as their influence on how people may respond to different treatments for addiction.
The ways in which prescription medications interact within our bodies may be influenced by several factors. We’ve become increasingly aware that the way a patient responds to certain drugs may, in some cases, be influenced by their unique, genetically-determined physiology and differences in various metabolic processes.
For example, a branch of pharmacology known as “pharmacogenetics” tells us that, because differences at a genetic level can cause patients to absorb, distribute, metabolize, and eliminate certain substances in very different ways, individuals may respond quite differently when given identical medications.8 For example, it’s possible that one patient might reap more therapeutic benefits from one pharmacologic treatment while another is left with merely a preponderance of side effects or a greater potential for adverse interactions.1,8 Genetics-informed treatment draws from this study of pharmacogenetics to better predict or determine how a person is likely to respond to different medications, in the hopes of one day being able to more precisely tailor treatment to each individual.
Greenhouse utilizes American Addiction Centers’ Addiction Labs of America to perform a series of lab tests for everyone admitted to treatment—including genetic tests within the first 24 hours to integrate any applicable findings into individualized treatment plans.10
This may enable prescribers to better estimate how individual patients will respond to different classes of medications, including some used for medication-assisted treatment, psychiatric medications used to treat co-occurring mental illness, and others potentially used to manage accompanying physical health issues. By personalizing prescription usage through genetics-informed treatment, prescribers may be able to lessen the likelihood of unpleasant side effects and minimize unnecessary trial and error that delays appropriate treatment.10
The Future of Genetics Research on Addiction Treatment
Right now, the standard of care for addiction treatment consists of a combination of behavioral therapeutic interventions and, when applicable, pharmacologic treatment (there are several FDA-approved medications used to treat alcohol and opioid dependence); people commonly maintain the recovery momentum initiated during treatment with ongoing aftercare efforts, which may consist of periodic counseling or therapy, support group meeting attendance, etc.
In the future though, gene therapy may play a vital role in helping to solve the addiction puzzle. Though the future impact of pharmacogenetics is promising, we might not be quite there yet.
Using pharmacogenetic data to hone medical care for addiction and other mental health issues is a promising avenue of modern treatment, and it’s certain that the scientific community will continue to build on this approach as we go forward.
Through a deeper understanding of individual physiological differences and other conferred addiction risks, it’s possible that new treatments will emerge that work by tempering neurochemical rewards associated with an addictive substance. As our knowledge deepens, we may also find better ways to design fully personalized treatment regimens through combinations of drugs specifically designed to target an individual’s unique addiction pathway.
Addiction is often a progressively destructive disease. The more treatment options we have at our disposal, the greater our chances of reducing its devastating toll.
- Addiction Labs of America. (n.d.). Spectra PGx—Personalized Diagnostic Solutions.
- U.S. National Library of Medicine—Genetics Home Reference. (2020). What is a gene?
- Understanding Genetics: A District of Columbia Guide for Patients and Health Professionals, Appendix G, Single-Gene Disorders. (2010). Washington (DC): Genetic Alliance.
- U.S. National Library of Medicine—Genetics Home Reference. (2020). What does it mean to have a genetic predisposition to a disease?
- American Society of Addiction Medicine. (2019). Definition of Addiction.
- Diagnostic and statistical manual of mental disorders: DSM-5 (5th ed.). (2013). Washington, D.C.: American Psychiatric Association.
- Dick, D. M., & Agrawal, A. (2008). The genetics of alcohol and other drug dependence. Alcohol research & health : the journal of the National Institute on Alcohol Abuse and Alcoholism, 31(2), 111–118.
- Miller, S. C., Fiellin, D. A., Rosenthal, R. N., & Saitz, R. (2019). The ASAM Principles of Addiction Medicine, Sixth Edition. Philadelphia: Wolters Kluwer.
- Foroud, T., Edenberg, H. J., Crabbe, J. C., (2010). Genetic Research—Who Is At Risk for Alcoholism? Alcohol Research & Health: The Journal of the National Institute on Alcohol Abuse and Alcoholism, 33(1;2):64-75.
- American Addiction Centers. (2020). Addiction Labs.
- Koromina, M., Koutsilieri, S., & Patrinos, G. P. (2020). Delineating significant genome-wide associations of variants with antipsychotic and antidepressant treatment response: implications for clinical pharmacogenomics. Human genomics, 14(1), 4.