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New booklet explains addiction
as a brain disease

Over the last decade, brain research has transformed our understanding of addiction.
"Drugs, Brains, and Behavior: The Science of Addiction"--a 30-page, color booklet from the National Institute on Drug Abuse (NIDA)--presents the latest findings on this topic.

"Thanks to science, our views and our responses to drug abuse have changed dramatically, but many people today still do not understand why people become addicted to drugs or how drugs change the brain to foster compulsive drug abuse," says Dr. Nora D. Volkow, NIDA director. "This booklet aims to fill that knowledge gap by providing scientific information about the disease of drug addiction in language that is easily understandable to the public."

"Drugs, Brains, and Behavior" highlights three specific aspects of addiction as a disease.

Drugs can disrupt signals between brain cells. Brain cells "talk" to each other by sending and receiving chemicals called neurotransmitters. This constant exchange of neurotransmitters affects every aspect of our thinking, feeling and behavior.

Drugs of abuse interfere with this normal exchange in many ways. For example, drugs may stop the brain from making neurotransmitters. Drugs can also bind to brain cells in place of neurotransmitters.

Some drugs, including cocaine and amphetamine, cause brain cells to release abnormally large amounts of neurotransmitters. "The difference in effect," note the report's authors, "can be described as the difference between someone whispering into your ear and someone shouting into a microphone."

Drugs can distort the brain's reward system. A portion of the brain called the limbic system regulates our feelings of pleasure. Signals between cells in the limbic system--sometimes called the "reward system"--reinforce us for eating, having sex, and other activities needed for human survival.

Drugs of abuse produce their effects by flooding cells in the reward system with dopamine, a neurotransmitter that produces pleasure. In fact, drugs can release up to 10 times the amount of dopamine produced by naturally rewarding behaviors.

The result is an increasing motivation to use drugs. As the report notes, "drug abuse is something we learn to do very, very well." For the person with this type of motivation, trying to give up cocaine or alcohol can seem as distant a goal as trying to give up food.

In order to cope with surges of dopamine and other neurotransmitters, the brain adapts by producing less dopamine and reducing the number of cells that transmit dopamine. When this happens, people need to use larger amounts of a drug to bring their dopamine levels back up to normal--and even more of the drug to get high.

Drugs can undermine decision-making. Images of drug addicts' brains show changes in areas that affect judgment and behavior control. This reflects a "double-whammy" of addiction--intense cravings for drugs paired with a compromised ability to make decisions.

For the addicted person, every day is dominated by the compulsion to get drugs and use drugs--no matter what the consequences. And, deciding to change these addictive behaviors by an act of sheer willpower becomes futile.

Understanding this fact reduces the stigma associated with addiction and underlines the need for medical treatment of the disease.

A diagnosis of addiction is not a life sentence. Treatment--behavioral therapy and medications--can help people manage changes in their brain function and respond to drug cravings in new ways. Group therapy and group support can enhance motivation to remain drug-free.

Because addiction treatment aims to change deeply embedded habits, relapse can be part of the process. However, this is a well-known feature of diabetes, hypertension, asthma, and other chronic diseases with treatment plans that depend on behavior change. Just as science is unraveling the causes of addiction, it is also revealing what works in helping people return over time to drug-free lives.

You can order a free copy of the NIDA booklet by calling the National Clearinghouse for Alcohol and Drug Information at 800-729-6686 or you can download a copy online at

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