Is Addiction a Disease?

Addiction, now often referred to as a substance use disorder (SUD), is a disease that involves the continued use of one or more substances even though there may be serious health and social consequences. Addiction interferes with parts of the brain that are responsible for reward, motivation, learning, judgment and memory.

The disease model of addiction

Addiction is defined as a disease by most medical associations, including the American Medical Association and the American Society of Addiction Medicine.

Like diabetes, cancer and heart disease, addiction is caused by a combination of factors.  These include behavioral, psychological, environmental and biological factors. The genes passed on by parents may also play a key role. They can be responsible for about half of a person’s risk of developing a substance use disorder.

When untreated, it can often cause other physical and mental health issues. Over time, addiction can become more severe, disabling and life-threatening.

How substance use changes the brain

People feel pleasure when basic needs, such as hunger and thirst, are satisfied. In most cases, these feelings of pleasure are caused by the release of certain chemicals in the brain. These chemicals reward the individual, making them repeat the behaviors that produce those feelings (like eating and drinking).

Substance use can cause the brain to release high levels of these same chemicals that cause feelings of pleasure. Constant substance use causes these chemicals to release more, which results in changes in the brain’s reward and motivation systems as well as memory.

As a person continues to use substances, the brain tries to get back to a balanced state by reacting less to those rewarding chemicals. As a result, a person may need to use more of the substance just to feel the same way they felt with lower amounts. This is called tolerance.

People may have strong desires or urges to use the substance even if there are harmful or dangerous consequences.  They may strain or ruin relationships with people who are concerned about their use.  Often people won’t do what they are supposed to do at home, school or work as substance use gets in the way. In addition, with some substances including heroin, fentanyl and other opioids, a person may continue to use to avoid feeling sick (known as experiencing withdrawal symptoms). They may also lose interest in normal life activities, hobbies and interests.

It takes time for the brain to heal from a substance use disorder. Because of this, those with a substance use disorder may be more at risk of returning to use due to triggers.  Triggers include people, places and things associated with substance use. Examples include places where a person used substances such as a bedroom, a car, or a bar.  Even an ATM can be triggering if a person used it to get money to buy substances. Certain people can trigger a desire to use substances or seeing substance use in a movie or on the street can result in urges to use.


Is substance use a choice?

Early decisions to use substances are based in large part on a person’s own choice, though this is often affected by their culture and environment. However, some people are more at risk of developing a SUD than others. This is caused by certain factors, such as:

When substance use progresses to the point of addiction, a person no longer chooses to use; they are now dependent on substances. A key sign of addiction is a loss of control over substance use.

Are people with addiction responsible for their actions?

A person doesn’t choose how their brain and body respond to substances. This is why some people can control their use and others can’t. People with a substance use disorder can still reduce their use or abstain — it’s just much harder than it is for others. Just like any other disease people need to be able to get quality, evidence-based treatment and care.

With the help and support of family, friends and peers to access help and stay in treatment, people struggling with a substance use disorder can increase their chances of recovery and survival. They can lead truly rewarding and fulfilling lives.

Addiction is a chronic disease

A chronic disease is a long-lasting condition that can be controlled but not cured.

Most people who engage in substance use do not develop addiction, and many young people tend to reduce their use once they take on more adult responsibilities. Still, about 25-50% of people with a substance use problem develop a severe, chronic disorder. For them, addiction is a disease that requires intensive treatments and continuing aftercare, monitoring and family or peer support to manage their recovery.

The good news is that even the most severe, chronic form of SUD can be manageable, usually with long-term treatment and continued recovery supports.

Why do some people say addiction is not a disease?

Some people think addiction cannot be a disease because it is caused by the individual’s choice to use substances. While the first use (or early use) may be by choice, once the brain has been changed by addiction, most experts believe that the person loses control of their behavior.

Choice does not determine whether something is a disease. Heart disease, diabetes and some forms of cancer involve personal choices like diet, exercise, sun exposure, etc. A disease is what happens in the body as a result of those choices.

Others argue that addiction is not a disease because some people with addiction get better without treatment. People with a mild SUD may recover with little or no treatment. People with the most serious form of SUD usually need intensive treatment followed by lifelong management of the disease. However, some people experiencing addiction stop drinking or using other substances without treatment. Others achieve recovery by attending self-help meetings without receiving much, if any, professional treatment.

In all cases, professional treatment and a range of recovery supports should be available and accessible to anybody who develops a substance use disorder. Addiction is a treatable disease.

Harm reduction

The ultimate goal for someone with an SUD may be to stop them from using substances entirely. However, it is important to take whatever steps you can to reduce the risks associated with substance use.

Strategies to move in a healthier direction include:

Doing this can help reduce the rate of overdoses, decrease the transmission of needle-related diseases, and connect people to substance use education. Read more about harm reduction strategies here.