Drug use (including alcohol) can cause changes in the brain's structure and function, turning substance abuse into addiction—a chronic, relapsing illness. Not everyone who uses alcohol, illicit drugs, or prescription drugs becomes addicted. Drugs differ in their addictive qualities. In addition, some people can become addicted more easily and quickly than others, especially those who have a family history or genetic susceptibility to addiction. From Abuse to Addiction When abuse becomes addiction, the addict suffers from a compulsive craving for the substance. He or she will do just about anything to obtain the drug, the National Institute on Drug Abuse says. Few addicts can quit by themselves, even when their use leads to serious physical and mental problems. Drug dependence can be psychological and physical. People who are psychologically dependent need their drug of choice to reach a basic level of functioning or well-being. Physical dependence relates to a person’s tolerance, dependence, and withdrawal symptoms when he or she stops using the substance. Recent Studies Research over the last decade reveals that addictive drugs and alcohol alter the function of the brain, the signals it generates, and the way brain cells work. As a result, normal thought processes, memory, and emotions are fundamentally affected and changed permanently. Once addicted, people risk their own survival to use the drug, and their desire becomes stronger than any natural drives, like that for food or sex. The drug becomes the most important part of the person's life, overshadowing any other aspect. When the rewired brain has experienced these changes, the desire will always be there. Studies have shown that no matter how long people have been clean and sober following active addiction, their brain cells will always have the potential to develop a full-fledged addiction if they ingest any amount of the substance again. That's why addiction is considered a chronic illness that has to be managed for the remainder of a person's life. Treatment The most effective treatments for substance addiction often combine medication, behavioral therapy, social services, and rehabilitation. Treatment for addiction doesn’t guarantee lifelong recovery from substance abuse. Relapse, which is often a part of the recovery process, is possible but can be treated. But even if someone who’s addicted to drugs or alcohol doesn’t achieve perfect abstinence, treatment that reduces the number of relapses and improves the person’s health and ability to cope with cravings is beneficial. If a friend or family member suffers from addiction, suggest the person see a doctor for an evaluation and help him or her find an appropriate treatment program. Understand that while the person made the choice to try drugs or alcohol, he or she didn't choose to become addicted. Your friend or family member needs medical treatment just as would anyone with a chronic illness, such as diabetes or heart disease.