Addiction, as defined by both the National Institute on Drug Abuse and the American Society for Addiction Medicine (ASAM), is a treatable, chronic medical disease that causes an individual to seek out and continually use drugs or engage in behaviors, even though doing so causes negative and harmful consequences.1,2
Addiction can be likened to other chronic diseases such as diabetes and COPD, and prevention efforts and treatment approaches for addiction are generally as successful as those for other chronic illnesses.1
How Drug Abuse Leads to Addiction
When individuals abuse drugs or alcohol repeatedly, changes occur in the brain that affect a person’s self-control, interfering with their ability to resist the urge to take drugs or drink alcohol.2,3
The brain’s “reward circuit” and its chemical messenger, dopamine, supports repeat behaviors that we as humans need to live a healthy life, such as eating or exercising or spending time with family and friends. Most drugs result in flooding the reward circuit with dopamine, reinforcing the unhealthy behavior of taking drugs and causing them to repeat the behavior.2
The brain eventually adapts, for example, by reducing the ability for cells in the reward circuit to respond to it. This effect is known as tolerance, and a person finds they need to take more and more of the drug to get the same feeling, or “high,” that they used to.2 It also often leads to the person deriving less pleasure from things they once enjoyed.
Chronic use of drugs can affect other aspects of the brain as well, affecting functions such as learning, judgment, decision-making, stress, memory, and behavior.2,3
The changes in the brain that result from long-term substance abuse can persist even after the individual stops using drugs and receives treatment for addiction. This speaks to just how powerful addiction can be and is the reason addiction is characterized as a chronic and relapsing disease.2,4
There are multiple factors that come into play when it comes to an individual being at risk for drug use and addiction. They include:
- Genetic predisposition/Biological factors: A person’s genetic makeup accounts for as much as half of an individual’s risk of becoming addicted to nicotine, alcohol or other drugs.5 This means that if an individual has family members who are dependent on drugs, they are at an increased risk of developing a substance use disorder.5 Other biological factors such as gender, ethnicity and the presence of other mental disorders may also influence a person’s addiction risk.2 Researchers are working to unravel the complex ways a person’s genetic makeup or biology could influence their risk of using drugs or becoming addicted to drugs.
- Environmental factors: Environmental factors play a role too.1 In fact, complex interactions between the environment and biological factors can affect the expression patterns of specific genes in a way that can affect human behavior.1,4
- Developmental factors: In the case of drug use, normal adolescent-specific behaviors such as risk taking and heightened sensitivity to peer pressure, can facilitate drug taking and greatly affect the way the teenager or young adult brain adapts, possibly putting them at greater risk of vulnerability to drug and/or alcohol abuse later in life.4
The Disease Debate
There’s no single factor that can predict whether a person will be vulnerable to the disease of addiction.1,2 That can be difficult to comprehend, and so there are, of course, people who think that addiction is a personal choice, and therefore should be discounted as an illness.
However, by taking a scientific and medical approach to addiction, researchers have been able to uncover many of the molecular circuits underlying addiction.3 This has led to several effective medications that help people suffering from addictions to certain substances, such as acamprosate for alcoholism and buprenorphine-naloxone for opioid addiction.3
Indeed, there is some level of personal choice involved in a person’s drug use, but that can also be said for many other chronic diseases that are caused or influenced by an individual’s life choices, such as heart disease, some forms of cancer, and diabetes. If an individual has a poor diet or chooses not to exercise, these choices can certainly affect an individual’s long-term health.
Like these other chronic illnesses, addiction also requires long-term treatment.4 Furthermore, the discontinuation of treatment for addiction, like other chronic diseases is likely to result in relapse.3
Interestingly, the relapse rate for addiction is similar to the relapse rate for other chronic diseases, as outlined below:6
- Substance use disorder relapse rate: 40-60%
- Hypertension relapse rate: 50-70%
- Asthma relapse rate: 50-70%
Given that addiction is a chronic disease, it should be monitored and treated over the course of an individual’s lifetime.1,7 Relapse is a normal part of recovery, and appropriate evidence-based treatment—both medication and behavioral—can be used to counteract addiction’s disruptive effects on the brain and help a person to regain control of their life.1,7
- American Society of Addiction Medicine. (2019). Definition of Addiction.
- National Institute on Drug Abuse. (2018). Understanding Drug Use and Addiction DrugFacts.
- Volkow, N. D., & Koob, G. (2015). Brain disease model of addiction: Why is it so controversial? The Lancet. Psychiatry, 2(8), 677–679.
- Miller, S. C., Fiellin, D. A., Rosenthal, R. N., & Saitz, R. (2019). The ASAM Principles of Addiction Medicine, Sixth Edition. Philadelphia: Wolters Kluwer.
- National Institute on Drug Abuse. (2019). Genetics and Epigenetics of Addiction.
- McLellan, A. T., Lewis, D. C., O’Brien, C. P., & Kleber, H. D. (2000). Drug dependence, a chronic medical illness: Implications for treatment, insurance, and outcomes evaluation. JAMA, 284(13), 1689–1695.
- National Institute on Drug Abuse. (2019). Drugs, Brains, and Behavior: The Science of Addiction. Treatment and Recovery.