Substance Use Disorders—A Disease of the Brain

In 2016, the United States Surgeon General issued the report: Facing Addiction in America: The Surgeon General’s Report on Alcohol, Drugs, and Health.  In the report, he defined “addiction” as:

The most severe form of substance use disorder, associated with compulsive or uncontrolled use of one or more substances. Addiction is a chronic brain disease that has the potential for both recurrence (relapse) and recovery. (emphasis added)

Also as noted by the Surgeon General in his report:

“[R]epeated misuse of any of these substances [alcohol, illicit drugs and over-the-counter drugs and other substances] can produce changes to the brain that can lead to a substance use disorder, an independent illness that significantly impairs health and function and may require specialty treatment.” (emphasis added)

On September 15, 2019, the American Society of Addition Medicine adopted their definition of “addiction” as:

Addiction is a treatable, chronic medical disease involving complex interactions among brain circuits, genetics, the environment, and an individual’s life experiences. People with addiction use substances or engage in behaviors that become compulsive and often continue despite harmful consequences. (emphasis added) 

Prevention efforts and treatment approaches for addiction are generally as successful as those for other chronic diseases.

These are not new breakthrough definitions of substance use disorders, commonly known as addiction.  These and other similar definitions are based on evidence from decades of research; they are definitions based on the science. 

Medical professionals around the globe recognize that a substance use disorder is a brain disease.  However, public opinion still lags behind.  It is time for that to change.

I Can’t Catch It—So It’s Not A Disease, It’s A Choice

When discussing this topic, common responses in opposition to substance use disorders being called a disease is, “I can’t catch it from someone, so it doesn’t count,” or “the ‘addict’ chose to use (insert your drug of choice),” meaning it was that person’s fault and their use shows a moral weakness.   However, these kinds of responses are very short sighted and narrow.  In other words, a substance use disorder is not like other diseases such as a cold or the flu. 

Consider the names listed below.  What do these names have in common, besides that they are well-known individuals?

• John Wayne (Actor)
• Nat King Cole (Singer)
• Yul Brynner (Actor)
• Betty Grable (Actor)
• George Harrison (Singer)
• Dean Martin (Singer)

If you guessed they all died of lung cancer you would be correct.  In the United States, it was estimated that over 140,000 people would die in 2019 from lung cancer.[1]  And what is the leading cause of lung cancer?  Smoking tobacco.[2]  Worldwide, approximately 1.5 million people die from cancer linked to tobacco.[3]  Smoking initially involves a voluntary choice to inhale a substance that can knowingly cause a dependency.

Skin cancer (melanoma) is another disease where the leading risk factor—sun or tanning beds—is because of human behavior.[4]  Tanning is a voluntary choice of lying on the beach or going to a sun tanner at a local business.

Hypertension, also called high blood pressure, is a disease that approximately 75 million Americans currently have.[5]  What are some of the causes for this disease?  While age and family history play a role, our choices can also be risk factors, such as eating an unhealthy diet, avoiding physical inactivity, being obese, or ingesting too much alcohol or using tobacco.[6] 

Hopefully the point is clear.  These accepted diseases can occur because of a person’s initial choices. These three diseases can happen because of our behavior, yet we don’t typically consider them a moral failing.  These three diseases cannot be passed from one person to another, yet we acknowledge them as a disease.

What Is A Disease?

At times when we first think of the word disease, we might think of the infectious diseases such as the Influenza, or Hepatitis C, or Tuberculosis which all can be spread, directly or indirectly, from one person to another. However, that is just one variation of a disease.  Maybe when you think of a disease, you think of a chronic disease such as heart disease, cancer or diabetes.  These are conditions that last a year or more and can require ongoing medical attention. [7] Suffice it to say that the term disease has a broad base for interpretation.

The Encyclopedia Britannica defines a disease as:

[A]ny harmful deviation from the normal structural or functional state of an organism, generally associated with certain signs and symptoms and differing in nature from physical injury. A diseased organism commonly exhibits signs or symptoms indicative of its abnormal state. Thus, the normal condition of an organism must be understood in order to recognize the hallmarks of disease.[8]

For example, with lung cancer, thanks to x-rays, we can see the cancer as it encompasses the lung.  After a person dies,  images of a person’s black encased lung can be seen because of the cancer and the smoking.  That cancer causes a ‘harmful deviation from the normal structure or functional state’ of the organism.  That is just as true for a substance use disorder.

A Re-Wired Brain

For centuries it was not possible to see what has happened to a person’s brain when a person has a substance use disorder.  Now it is.  Thanks to advances in technology, we can see how a brain changes from its normal structure.  Now we know that a substance use disorder changes the brain and impairs how it works for the long-term.

We know that certain actions or substances can cause us to feel pleasure.  In fact, there are certain activities that are considered “primary reinforcers,” such as: water, food, sleep, air and sex.  These primary reinforcers are fundamental to the wellbeing and survival of humanity; they are biological in nature.  

When we experience pleasure the brain releases a chemical called dopamine into certain receptors in the brain’s pleasure center.  The primary reinforcers are all things that can result in a release of dopamine.  Something that causes a release of the dopamine typically becomes something we like.  Initially, some substances, drugs, can cause pleasure and result in dopamine being released.  In some situations, drugs will release more dopamine than is normal when compared to a primary reinforecer.  As a result, a person who uses that substance likes it; it initially feels good.  However, as time passes, the brain starts to change; the person’s brain adapts to the release recognizing that the overstimulation is not normal.   Because of the overstimulation, and to seek a type of balance, the brain starts to shut down the amount of dopamine it produces and the receptors that respond to it.  Not experiencing the same pleasure, the person starts to take greater amounts or stronger drugs trying to achieve that same feeling of pleasure he first felt.  In response, the brain shuts down more receptors.    

The problem then is that the brain actually starts to crave that drug.  While not as significant as that first rush, there is no feeling of pleasure without the drug’s presence.  The brain now demands the chemical rush; it no longer “likes” the drug, it “wants” the drug.  The brain demands that drug. Prolonged drug use changes the brain in fundamental ways; rewiring it to the point where certain parts of the brain are no longer active. The organism is no longer working in its normal or functional state. 

There have been a significant number of brain scans showing the differences between a “normal” brain and one suffering a substance use disorder.  A couple of the images of those scans are included in this posting. It is these kinds of scans that have led the understanding of what a substance use disorder is and how it impacts the brain.

Because of the rewiring of the brain, it is no longer a choice or a lack of willpower that causes the person to use; they use because it has become more important to have that substance than to eat or sleep.[9]

Now What?

There is no single factor that will predict if someone will become dependent to a particular substance.  It is also not clear who will successfully quit because of possibly attending a 12-step program such as NA (Narcotics Anonymous) or those who will need more support such as in-house treatment.  It is a complex issue.  

But for most people suffering a substance use disorder, there are a number of steps that can be taken to treat the disorder so a person can live a successful and drug-free life.[10]  Like some other diseases, by removing the use of that drug, the brain can heal over time. (Over time means months and years, not days or weeks.)  During that time there are still a number of issues to work on, such as possible “triggers” and how to prevent relapse (which happens), but it is possible to heal.

As an aside, it would also seem a reasonable expectation that by recognizing a substance use disorder as a disease, we can reduce the stigma attached to a person with a substance use disorder[11] and provide the resources necessary to respond to it.

So consider the next time you hear the word “addict” or see someone who is dependent on a particular substance that that person’s mind is not working as it was intended, because of the substance use disorder.  The brain was rewired from the drug use. In other words, the person has a disease and needs support to find the way to change his or her behavior.

Footnotes:

[1] Key Statistics for Lung Cancer, American Cancer Society

[2] What Causes Lung Cancer? American Cancer Society

[3] Cancer—Key Statistics, World Health Orginazation

[4] Melanoma Risk Factors, Skin Cancer Foundation

[5] High Blood Pressure Frequently Asked Questions, Centers for Disease Control and Prevention

[6] Behaviors that Increase Risk for High Blood Pressure, Centers for Disease Control and Prevention

[7] About Chronic Diseases, National Center for Chronic Disease Prevention and Health Promotion

[8] Diseases, Encyclopedia Britannica

[9] The Science of Drug Use: Discussion Points, National Institute on Drug Abuse

[10] See Step by Step Guides to Finding Treatment for Drug Use Disorders, National Institute on Drug Abuse

[11] See also JSI Blog posts:  A Rose by Any Other Name, and Words Matter: Changing Our Language on “Addiction”