Teen Space

Addiction and the Brain
How To Recognize a Substance Use Disorder
Addiction and the Brain

Revised June 2019

Your Brain

Conceptual image of a man from side profile showing brain and brain activity©Shutterstock/ Triff

Your brain is who you are. It’s what allows you to think, breathe, move, speak, and feel. It’s just 3 pounds of gray-and-white matter that rests in your skull, and it is your own personal “mission control.”

The brain is always working, even when you’re sleeping. Information from your environment makes its way to the brain, which receives, processes, and integrates it so that you can survive and function under all sorts of changing circumstances and learn from experience. This information comes from both outside your body (like what your eyes see and skin feels) and inside (like your heart rate and body temperature).

The brain is made up of many parts that all work together as a team. Each of these different parts has a specific and important job to do. When drugs enter the brain, they interfere with its normal tasks and can eventually lead to changes in how well it works. Over time, drug use can lead to addiction, a devastating brain disease—when people can’t stop using drugs even when they really want to, and even after it causes terrible consequences to their health and other parts of their lives. (Learn more about the brain-body connection.)

Drugs affect mostly three areas of the brain:

  • The brain stem is in charge of all the functions our body needs to stay alive—breathing, moving blood, and digesting food. It also links the brain with the spinal cord, which runs down the back and moves muscles and limbs. It also lets the brain know what’s happening to the body.
  • The limbic system links together a bunch of brain structures that control our emotional responses, such as feeling pleasure when we eat chocolate or kiss someone we love. The good feelings motivate us to repeat the behavior, which can be good because things like eating and love are critical to our lives.
  • The cerebral cortex is the mushroom-shaped outer part of the brain (the gray matter). In humans, it is so big that it makes up about three-fourths of the entire brain. It’s divided into four areas, called lobes, which control specific functions. Some areas process information from our senses, allowing us to see, feel, hear, and taste. The front part of the cortex, known as the frontal cortex or forebrain, is the thinking center. It powers our ability to think, plan, solve problems, and make decisions.

How does your brain communicate?

Nuerons: Building Blocks of the Brain. The brain is made up of billions of nerve cells, also known as neurons. Neurons communicate with other neurons through a process known as neurotransmission.

The brain is a complex communications network of billions of neurons, neurotransmitters, and receptors. Networks of neurons pass messages back and forth thousands of times a minute within the brain, spinal column, and nerves. These nerve networks control everything we feel, think, and do. For example, when you want to go up the stairs, this message system will tell you to lift your foot onto the first step and so on. Understanding these networks helps scientists learn how drugs affect the brain. The networks are made up of:

  • Neurons
    Your brain contains about 100 billion neurons—nerve cells that work nonstop to send and receive messages. Within a neuron, messages travel from the cell body down a nerve fiber called an axon in the form of electrical impulses. From there, the message is sent to other neurons.
  • Neurotransmitters—The Brain’s Chemical Messengers
    To help those messages travel from one neuron to another, the brain creates chemical messengers called neurotransmitters. Branches of the axon, called axon terminals, release neurotransmitters into the space between two nerve cells, called a synapse. The axon terminal is like the bus or train terminal – a transportation hub of activity.
  • Receptors—The Brain’s Chemical Receivers
    A cartoon depiction of how brain cells communicate.To send a message, a nerve cell releases a chemical (neurotransmitter) into the space separating two nerve cells, called the synapse. The neurotransmitter crosses the synapse and attaches to proteins (receptors) on the receiving nerve cell. This causes changes in the receiving nerve cell, and the message is delivered.

    As the neurotransmitter approaches the nearby neuron, it attaches to a special site on that neuron called a receptor. A neurotransmitter and its receptor operate like a key and lock— a very specific mechanism makes sure that each receptor will forward the right message only after interacting with the right kind of neurotransmitter.

  • Transporters—The Brain’s Chemical Recyclers
    Once neurotransmitters do their job, they are pulled back into their original neuron by transporters. This recycling process shuts off the signal between the neurons.

How do drugs affect your brain?

Drugs are chemicals. When someone puts these chemicals into their body, either by smoking, injecting, inhaling, or eating them, they tap into the brain’s communication system and tamper with the way nerve cells normally send, receive, and process information. Different drugs—because of their chemical structures—work differently. We know there are at least two ways drugs work in the brain:

  • Imitating the brain’s natural chemical messengers
  • Overstimulating the “reward circuit” of the brain

Some drugs, like marijuana and heroin, have chemical structures that mimic a neurotransmitter that naturally occurs in our bodies. In fact, these drugs can “fool” our receptors, lock onto them, and activate the nerve cells. However, they don’t work the same way as a natural neurotransmitter, and the neurons wind up sending abnormal messages through the brain, which can cause problems both for our brains and our bodies.

Other drugs, such as cocaine and methamphetamine, cause nerve cells to release too much dopamine, a natural neurotransmitter, or prevent the normal recycling of dopamine. This leads to exaggerated messages in the brain, causing problems with communication channels. It’s like the difference between someone whispering in your ear versus someone shouting in a microphone.

The “High” From Drugs/Pleasure Effect

Scientists used to assume that the rush of dopamine alone caused the feeling of euphoria (happiness) during drug use, but they now know it is more complicated than that. Many drugs—nicotinecocainemarijuana, and others—affect the brain’s “reward” circuit, which is part of the limbic system. Normally, the reward circuit responds to healthy, pleasurable activities by releasing the neurotransmitter dopamine, which teaches other parts of the brain to repeat those activities. Drugs take control of this system, releasing large amounts of dopamine—first in response to the drug but later mainly in response to other cues associated with the drug—like being with people you used drugs with, or being in places where you used drugs. The brain remembers this feeling and sends out an intense motivation to seek and use the drug again. So dopamine does not cause the rush of feelings; instead it reinforces the desire to use drugs.

The Repeat Effect

Our brains are wired to make sure we will repeat survival activities, like eating, by connecting those activities with feeling good. Whenever this reward circuit is kick-started, the brain notes that something important is happening that needs to be remembered, and teaches us to do it again and again, without thinking about it. Because drugs come in and “hijack” the same circuit, people learn to use drugs in the same way.

After repeated drug use, the brain starts to adjust to the surges of dopamine. Neurons may begin to reduce the number of dopamine receptors or simply make less dopamine. The result is less dopamine signaling in the brain—like turning down the volume on the dopamine signal. Because some drugs are toxic, some neurons also may die.

As a result, the ability to feel pleasure is reduced. The person feels flat, lifeless, and depressed, and is unable to enjoy things that once brought pleasure. Dopamine encourages the brain to repeat the pleasurable activity of drug taking to feel good again. Now the person needs drugs just to feel normal, an effect known as tolerance.

Watch our video Why Are Drugs So Hard To Quit? to learn more.

Long-Term Effects

Drug use can eventually lead to dramatic changes in neurons and brain circuits. These changes can stay even after the person has stopped taking drugs. This is more likely to happen when a drug is taken over and over again.

What is drug addiction?

Addiction is a chronic brain disease that causes a person to take drugs or alcohol repeatedly, despite the harm they cause. The first time a person uses drugs, it’s usually a free choice. However, repeated drug use can change the brain, driving a person to seek out and use drugs over and over, despite negative effects such as stealing, losing friends, family problems, or other physical or mental problems brought on by drug use. This is addiction.

What factors increase the risk for addiction?

Although we know what happens to the brain when someone becomes addicted, we can’t predict how many times a person must use a drug before becoming addicted. A combination of factors related to your genes, environment, and your personal development increases the chance that taking drugs will lead to addiction. These include:

  • Home and family. Parents or older family members who use alcohol or drugs, or who are involved in criminal behavior, can increase a young person’s risk for developing a drug problem.
  • Peers and school. Friends and acquaintances who use drugs can sway young people to try drugs for the first time. Academic failure or poor social skills can also put a person at risk for drug use.
  • Early use. Although taking drugs at any age can lead to addiction, research shows that the earlier a person begins to use drugs, the more likely they are to progress to more serious use. This may reflect the harmful effect that drugs can have on the developing brain. It also may be the result of early biological and social factors, such as genetics, mental illness, unstable family relationships, and exposure to physical or sexual abuse. Still, the fact remains that early drug use is a strong indicator of problems ahead—among them, substance use and addiction.
  • Method of use. Smoking a drug or injecting it into a vein increases its addictive potential. Both smoked and injected drugs enter the brain within seconds, producing a powerful rush of pleasure. However, this intense “high” can fade within a few minutes, and the person no longer feels good. Scientists believe that this low feeling drives people to repeat drug use in an attempt to recapture the high pleasurable state.

Learn more about what puts you at risk, view our video Anyone Can Become Addicted to Drugs.

Can you die if you use drugs?

Yes, deaths from drug overdose have been rising steadily over the last decade, largely due to increases in misuse of opioids. In 2017, more than 70,200 people died from a drug overdose, significantly more than the 63,000 people who died the year before. More than three out of five of those drug overdose deaths involved some type of opioid, either prescription pain reliever, heroin, or human-made opioids like fentanyl. Among young people ages 15-24, just over 5,400 deaths from a drug overdose occurred in 2017.1 Young males were two times more likely to die from a drug overdose than were females.

In addition, death can occur from the long-term effects of drugs. For example, long term use of tobacco products can cause cancer, which may result in death. Learn more about drug overdoses in youth

1 Centers for Disease Control and Prevention, National Center for Health Statistics. Underlying Cause of Death 1999-2017 on CDC WONDER Online Database, released 2018. Available at http://wonder.cdc.gov.

Are there effective treatments for drug addiction?

Yes, there are treatments to help manage addiction, but there is no cure. It is considered a chronic disease, meaning it lasts a long time and needs to be managed with regular treatment. If people follow treatment plans, they can go for many years leading healthy lives. It can be similar to other chronic conditions that people learn to manage, like diabetes or heart disease. Scientific research has shown that 13 basic principles are the foundation for effective drug addiction treatment. Find out more in Principles of Adolescent Substance Use Disorder Treatment: A Research-Based Guide.

Types of Treatment

Treatment will vary for each person, depending on the type of drugs used and the person’s specific circumstances. Generally, there are two types of treatment for drug addiction:

  • Behavior change— helping people learn to change behaviors that trigger drug use
  • Medications— helping people manage cravings for some drugs, such as tobacco, alcohol, heroin, or other opioids

Length of Treatment

Most people who have become addicted to drugs need long term treatment and, many times, repeated treatments—much like a person who has asthma needs to constantly watch the effects of medication and exercise. Even when someone relapses and begins using drugs again, they should not give up hope— they might need to change to a different treatment plan. In fact, setbacks are likely. Even people with diabetes may go off their diet or miss an insulin injection, and their symptoms will recur—that’s a cue to get back on track, not to view treatment as a failure.

Motivation for Treatment

Most people go into drug treatment either because a court ordered them to do so or because loved ones wanted them to seek treatment. Many people are tired of addiction and its problems, and chose to go into treatment. Others are ordered into treatment by a judge or under pressure from family members.

How do I know if someone has a drug problem?

The signs listed below may suggest a developing problem, which you should discuss with an adult you trust:

  • hanging out with different friends
  • not caring about your appearance
  • getting worse grades in school
  • missing classes or skipping school
  • losing interest in your favorite activities
  • getting in trouble in school or with the law
  • having different eating or sleeping habits
  • having more problems with family members and friends

Questions to Ask: Do You Have a Problem? 

Answering yes to any of the following questions may indicate a problem:

  1. Have you ever ridden in a car driven by someone (including yourself) who had been using alcohol or drugs?
  2. Do you ever use alcohol or drugs to relax, to feel better about yourself, or to fit in?
  3. Do you ever use alcohol or drugs when you are alone?
  4. Do you ever forget things you did while using alcohol or drugs?
  5. Do family or friends ever tell you to cut down on your use of alcohol or drugs?
  6. Have you ever gotten into trouble while you were using alcohol or drugs?

What should I do if someone I know needs help?

If you, or a friend, are in crisis and need to speak with someone now: 

  • Call the National Suicide Prevention Lifeline at 1-800-273-TALK (they don’t just talk about suicide—they cover a lot of issues and will help put you in touch with someone close by)

If you want to help a friend, you can:

If a friend is using drugs, you might have to step away from the friendship for a while. It is important to protect your own mental health and not put yourself in situations where drugs are being used.

How To Recognize a Substance Use Disorder

How To Recognize a Substance Use Disorder

How do I know if I have a drug use problem?

Samhsa.gov treatment locator

Addiction can happen at any age, but it usually starts when a person is young.  If you continue to use drugs despite harmful consequences, you could be addicted. It is important to talk to a medical professional about it—your health and future could be at stake.

Have friends or family told you that you are behaving differently for no apparent reason—such as acting withdrawn, frequently tired or depressed, or hostile? You should listen and ask yourself if they are right—and be honest with yourself. These changes could be a sign you are developing a drug-related problem. Parents sometimes overlook such signs, believing them to be a normal part of the teen years. Only you know for sure if you are developing a problem because of your drug use. Here are some other signs: 

  • hanging out with different friends
  • not caring about your appearance
  • getting worse grades in school
  • missing classes or skipping school
  • losing interest in your favorite activities
  • getting in trouble in school or with the law
  • having different eating or sleeping habits
  • having more problems with family members and friends

There is no special type of person who becomes addicted. It can happen to anyone. (See NIDA’s video below)

Thanks to science, we know more than ever before about how drugs work in the brain, and we also know that addiction can be successfully treated to help young people stop using drugs and lead productive lives. Asking for help early, when you first suspect you have a problem, is important; don’t wait to become addicted before you seek help.  If you think you are addicted, there is treatment that can work. Don’t wait another minute to ask for help.

Why can’t I stop using drugs on my own?

Repeated drug use changes the brain. Brain imaging studies of drug-addicted people show changes in areas of the brain that are needed to learn and remember, make good decisions, and control yourself. Quitting is difficult, even for those who feel ready. NIDA has an excellent video (below) that explains why drugs are so hard to quit (hint: it’s all about the brain). If you aren’t sure you are addicted, it would be helpful for you to look at this brief video. It helps explains why your inability to stop using drugs does not mean you’re a bad person, just that you have an illness that needs to be treated.

Why Are Drugs So Hard to Quit?

I don’t feel well when I stop using drugs. Do treatment centers force people to stop taking drugs immediately?

Treatment is always based on the person’s needs. However, if you are still using a drug when you are admitted to a treatment program, one of the first things addiction specialists need to do is help you safely remove drugs from your system (called “detox”). This is important because drugs impair the mental abilities you need to make treatment work for you.

When people first stop using drugs, they can experience different physical and emotional withdrawal symptoms, including depression, anxiety, and other mood disorders, as well as restlessness and sleeplessness. Remember that treatment centers are very experienced in helping you get through this process and keeping you safe and comfortable during it. Depending on your situation, you might also be given medications to reduce your withdrawal symptoms, making it easier to stop using.

I tried rehab once and it didn’t work—why should I try it again?

If you have already been in rehab, it means you have already learned many of the skills needed to recover from addiction, and you should try it again. Relapsing (going back to using drugs after getting off them temporarily) does not mean the first treatment failed. People with all kinds of diseases relapse; people with other chronic diseases such as high blood pressure and asthma—which have both physical and behavioral components—relapse about as much as people who have addictions.

Treatment of all chronic diseases, including addiction, involves making tough changes in how you live and act, so setbacks are to be expected along the way. A return to drug use means treatment needs to be started again or adjusted, or that you might need a different treatment this time.

I don’t like lying to my parents but, they don’t understand me and my problems. If we talk about drugs, they will just yell at me. How can I avoid a fight?

First of all, remember that they were teens once, and they understand teen life more than you think. Secondly, when you first tell them about your problem, they might get angry out of fear and worry. They might raise their voices because they are very, very worried about you and your future. Try to stay calm and simply ask for help. Repeat over and over again that you need their help.

Parents do get angry when they find out their kids have been lying to them. You’d do the same! Be honest with them. Let them know you want to change and need their help.

I am also afraid my parents will take away the car keys—what can I do about that?

The single most responsible thing you can do is stop driving until you get help for your drug use. This might be inconvenient, but if you do drugs and drive, you could end up not only killing yourself but killing others as well. That could lead to a lifetime in prison. This is no different than drinking and driving. For more see our DrugFacts on drugged driving.

If you tell your parents that you are willing to give up your driving privileges, they will know you are serious about getting help.

What are effects of Drugs on Driving?

Taking drugs helps me feel less depressed—what’s wrong with that?

The relief you feel is only temporary and can cause more problems down the road, as your brain and body start to crave more and more drugs just to feel normal.  It is very possible you need to find treatment for your depression as well as for your drug use. This is very common. It is called “comorbidity” or “co-occurrence” when you have more than one health problem at the same time. For more information, see Drug Facts for Teens Co-Occurring Substance Use and Other Mental Health Issues

Be certain to tell your doctor about your drug use, as well as any depression or anxiety you feel, or any other mental health issues you are experiencing. There are many nonaddictive medicines that can help with depression or other mental health issues. Sometimes doctors do not talk to each other as much as they should. For example, a therapist you might be seeing for depression does not always consult with your pediatrician. So you need to be your own best friend and advocate—and make sure all of your health care providers know about all of the health issues that concern you. You should be treated for all of them at the same time.

Note: If you ever feel so depressed that you think about hurting yourself, there is a hotline you can call: 1-800-273-TALK (8255). This is called the National Suicide Prevention Lifeline, and you can share all of your problems with them. A caring, nonjudgmental voice will be on the other end, listening.