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.” Information from your environment—both outside (like what your eyes see and skin feels) and inside (like your heart rate and body temperature)—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. The brain is always working, even when you're sleeping.
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 processing and can eventually lead to changes in how well it works. Over time, drug use can lead to addiction, a devastating brain disease in which 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.
Drugs affect three primary areas of the brain:
How does the Brain Communicate
The brain is a complex communications network of billions of neurons, or nerve cells. 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. Understanding these networks helps in understanding how drugs affect the brain. The networks are made up of:
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:
Some drugs, like marijuana and heroin, have chemical structures that mimic that of 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 as well as our bodies.
Other drugs, such as cocaine and methamphetamine cause nerve cells to release too much dopamine, which is 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
Most drugs of abuse—nicotine, cocaine, marijuana, and others—affect the brain’s “reward” circuit, which is part of the limbic system. Normally, the reward circuit responds to feelings of pleasure by releasing the neurotransmitter dopamine.Dopamine creates feelings of pleasure. Drugs take control of this system, causing large amounts of dopamine to flood the system. This flood of dopamine is what causes the “high” or intense excitement and happiness (sometimes called euphoria) linked with drug use.
The Repeat Effect
Our brains are wired to make sure we will repeat healthy 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 of abuse 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 any pleasure is reduced. The person feels flat, lifeless, and depressed, and is unable to enjoy things that once brought pleasure. Now the person needs drugs just to bring dopamine levels up to normal, and more of the drug is needed to create a dopamine flood, or “high”—an effect known as “tolerance.”
Drug use can eventually lead to dramatic changes in neurons and brain circuits. These changes can still be present even after the person has stopped taking drugs. This is more likely to happen when a drug is taken over and over.
What is drug addiction?
Addiction is a chronic brain disease that causes a person to compulsively seek out drugs, despite the harm they cause. The first time a person uses drugs, it’s usually a free choice they’ve made. However, repeated drug use causes the brain to change which drives 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 development increase the chance that taking drugs can lead to addiction:
Can you die if you use drugs?
Yes, deaths from drug overdose have been rising steadily over the last decade. In 2015 alone, more than 52,400 people died from a drug overdose. More than three out of five drug overdose deaths involve some type of opioid, either prescription pain reliever, heroin, or man-made opioids like fentanyl. Among young people, just over 4,200 deaths from a drug overdose occurred that year. Young males were two times more likely to die from a drug overdose than were females. Learn more about drug overdoses in youth.
In addition, death can occur from the long-term effects of drugs. For example, use of tobacco products can cause cancer, which may result in death.
Are there effective treatments for drug addiction?
Yes, there are treatments, but there is no cure for drug addiction yet. Addiction is often a disease that is long-lasting (sometimes referred to as chronic). As with other chronic diseases, like diabetes or heart disease, people learn to manage their condition. Scientific research has shown that 13 basic principles are the foundation for effective drug addiction treatment.
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:
Length of Treatment
Like diabetes and even asthma, drug addiction typically is a long-lasting disorder. 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 changes in medication and exercise. The important point is that even when someone relapses and begins abusing drugs again, they should not give up hope. Rather, they need to go back to treatment or change their current treatment. 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. The good news is that, according to scientific studies, people can benefit from treatment regardless of whether or not they chose to go into treatment.
How do I know if someone has a drug problem?
There are questions people can ask to gauge whether or not a person has a drug problem. These may not mean that someone is addicted but answering yes to any of these questions may suggest a developing problem, which could require followup with a professional drug treatment specialist. These include:
If you, or a friend, are in crisis and need to speak with someone now:
If you need information on drug treatment and where you can find it, the Substance Abuse and Mental Health Services Administration can help.
Thom Kessler, LMFT, RAS
Marriage & Family Therapist and Registered Addiction Specialist