Addiction is a chronic brain disease that causes people to lose their ability to resist a craving, despite negative physical, personal, or social consequences. People seek out nicotine and alcohol, or engage in gambling, because it makes them feel good or lessens feelings of stress and sadness. Many abused drugs produce a pleasurable feeling by exciting cells in the brain’s reward center. With repeated use, drugs can change the structure of the brain and its chemical makeup. But why can some people casually drink alcohol or smoke cigarettes, while others fight to kick the habit?
Neuroscience research, both in human and animal studies, is helping scientists identify key factors that influence susceptibility to addiction, such as a person’s genetic makeup, vulnerability to stress, and the age they start engaging in the behavior. Slowly but surely, new studies are unraveling clues about processes in the brain that influence the likelihood of drug relapse. Such insights may help improve rehabilitation programs and drive down the global cost of addiction.