Why Do Some People Become Addicted?

For two decades, researchers have been struggling to identify the biological and environmental risk factors that can lead to addiction to alcohol and other drugs. These factors form a complex mélange in which the influences combine to bring about addiction and to make its treatment challenging. But scientists know more about addiction now than they did even 10 years ago, and have learned much about how the risk factors work together.

The widely recognized risk factors include:

Genes: Genetics play a significant role: having parents with alcoholism, for instance, makes you four times more likely than other children to become alcoholics. More than 60 percent of alcoholics have family histories of alcoholism.

Mental illness: Many addicted people also suffer from mental health disorders, especially anxiety, depression or mood illnesses.

Early use of alcohol or drugs: The earlier a person begins to use alcohol or drugs the more likely they are to progress to more serious abuse.

Social environment: People who live, work or go to school in an environment in which the use of alcohol and other drugs is common - such as a workplace in which people see heavy drinking as an important way to bond with coworkers - are more likely to abuse drugs.

Childhood trauma: Scientists know that abuse or neglect of children, persistent conflict in the family, sexual abuse and other traumatic childhood experiences can shape a child's brain chemistry and subsequent vulnerability to addiction.

"The kids most likely to get addicted are the ones who also have other problems," says Dr. Mark Willenbring, who directs the Division of Treatment and Recovery Research of the National Institute on Alcohol Abuse and Alcoholism (NIAAA). Forty percent of people who start drinking before they are 15 years old develop alcoholism.

Addiction is at the end of a spectrum of substance use problems; for most people, though not all, addiction arrives after other phases of drinking or drugging go uninterrupted. That's why it is so important to treat substance use problems in their earliest stages. Although genetic researchers are trying to identify the genes that confer vulnerability to alcoholism, this task is difficult because the illness is thought to be related to many different genes, each of which contributes only a portion of the vulnerability.

The Addiction Project
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