Is addiction really a disease or a matter of choice? Ask the mother who lost her 19-year-old son — the laughing family prankster who earned a full-ride college scholarship as a solid student and star second baseman — to drugs.

The moody, angry dropout who survived overdoses to get caught breaking into cars wasn’t the boy she raised. What she knew, like the families and friends of the more than 15,000 Hoosiers who’ve died due to overdose since 1999, is that addiction’s not a life anyone would choose.

Most medical professionals agree. The American Medical Association (AMA) classified alcoholism as a disease in 1956 and included addiction as a disease in 1987.

In 2011 the American Society of Addiction Medicine (ASAM) joined the AMA, defining addiction as a chronic brain disorder, not a behavior problem, or just the result of making bad choices.

Research and input from top addiction authorities, addiction medicine doctors, neuroscientists and experts from the National Institute on Drug Abuse are behind classifying addiction as a disease. Like other chronic diseases such as diabetes and heart disease, experts are still learning about how and why the disease develops. Let’s look at what they know so far.

What is addiction?

Alcohol or drug addiction, also known as substance use disorder, is a chronic disease of the brain that can happen to anyone. Severe substance use disorder happens when substance use becomes an uncontrollable habit that hurts your day-to-day life, showing up as struggles at work or in school, conflicts with relationships, legal or money problems.

Addiction changes the brain

Addiction changes the way the brain works, rewiring its structure. Drugs and alcohol hack into your brain’s communication system and interfere with how nerve cells send, receive and process information.

Parts of the brain make up our reward system. They’re in charge of rewarding us when we do something we like—eating a piece of our favorite pie, hanging out with friends, going for a run, for instance. That reward comes in the chemical dopamine, which the brain releases when we do something enjoyable.

The reward system remembers then asks for more

Dopamine makes us feel good and want to keep doing what we’re doing. It also teaches the brain to repeat the behavior. Cues trigger the reward system, fuel cravings and create a habit loop. The smell of pie baking can have you salivating and anticipating the taste delight that’s coming. Addiction fuels habits too—craving a cigarette every morning with coffee or wanting a hit when you drive past the house where you used to do drugs.

When you take a drug, your brain releases a flood of dopamine, way more than it would when you’re eating your favorite pie, for instance. Your brain overreacts and cuts back on dopamine production to bring it down to a normal level.

As you continue to use drugs, your body produces less dopamine. Things that brought you pleasure—that pie, friends, and even drugs—don’t anymore. Once you’re addicted, it takes more and more drugs just to feel normal.

An addicted brain impacts behavior, too

Research has shown how addiction changes the areas of the brain in charge of judgment, decision making, learning and memory, and controlling behavior. Those changes can lead to a good student flunking out, a wife lying about draining the family savings account or an overdose in a grocery parking lot, with kids watching from their car seats.

Once substance use changes the brain, willpower changes too. If you try to quit using substances, your brain tries to protect you from the pain and intensity of withdrawal symptoms. Addiction fuels your brain’s response to do whatever it takes to stop the cravings and discomfort. That can mean overruling the will to “just say no” by taking a drink or using a drug.

Addiction is a chronic disease that involves different factors

A disease is a condition that changes the way an organ functions. Chronic disease can be treated and managed, but it can’t be cured. Addiction is a chronic disease of the brain the way diabetes is a chronic disease of the pancreas, and heart disease is one of the heart.

Addiction doesn’t discriminate. High-rent districts, “seedy” neighborhoods, age, race, sex or how much money you make—addiction weaves its way through all walks of life. No one thing can predict your risk of developing a substance use disorder. But researchers agree there are a combination of factors involved that can increase your risk:

• Genetics—Yes, if addiction runs in the family, the National Institute on Drug Addiction says you have up to a 60% greater risk of becoming addicted too.
• Environment—Just like growing up in a home where fried foods, soda and sugary sweets increase your risk for heart disease and diabetes, growing up in a home with adults who use drugs increases the risk of addiction.
• Development—Using drugs as a teenager up to age 25 when the brain is still developing increases your chances of addiction and can cause serious, lasting damage.

Addiction isn’t a choice, but treatment is

Everyone makes a choice about using drugs or taking a drink for the first time. You don’t have a choice about how your brain reacts, however. When substance use rewires your brain, your ability to make good decisions gets hijacked.

Willpower and shaming won’t undo the changes in the brain and cure addiction. There is no cure, but treatment helps you manage and successfully live with the disease.

Just as someone with diabetes or heart disease has to choose to exercise and change to a healthy diet to control their disease, someone with addiction has to choose treatment. A court order or family’s ultimatum may be behind that choice. But often, someone chooses on their own, wanting a life without addiction and the problems that come with it more than the drugs.

Scientists don’t know why some people can successfully quit using drugs on their own, and others can’t. For most people, recovery takes treatment that includes behavioral therapy and often, medications to help control cravings and help the brain adapt to functioning without drugs.

Relapses are a reality, but they’re not failure

Getting sober is hard. Staying on track is too. That’s the nature of living with a chronic disease. Success takes managing the changes in the brain and learning how to change deeply rooted behaviors. And then the toughest part for many: committing to managing new behaviors for the rest of your life.

Sometimes it’s too much. Relapses happen, often many times. They’re not a treatment failure, but a cue to get back on track. That can mean making adjustments with or changing treatment.