The disease model of addiction
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:
- A family history of addiction
- Untreated treated mental health disorders such as depression and anxiety
- Family conflict
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?
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?
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:
- Using fentanyl test strips
- Clean and sterile needle exchanges
- Carrying naloxone
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.