En español
NIDA

Bringing the Power of Science to Bear on Drug Abuse and Addiction

2: The memory of drugs

The memory of drugs Photo courtesy of Anna Rose Childress, Ph.D.

This image demonstrates something really amazing - how just the mention of items associated with drug use may cause an addict to “crave” or desire drugs. This PET scan is part of a scientific study that compared recovering addicts, who had stopped using cocaine, with people who had no history of cocaine use. The study hoped to determine what parts of the brain are activated when drugs are craved.

For this study, brain scans were performed while subjects watched two videos. The first video, a nondrug presentation, showed nature images - mountains, rivers, animals, flowers, trees. The second video showed cocaine and drug paraphernalia, such as pipes, needles, matches, and other items familiar to addicts.

This is how the memory of drugs works: The yellow area on the upper part of the second image is the amygdala (a-mig-duh-luh), a part of the brain’s limbic system, which is critical for memory and responsible for evoking emotions. For an addict, when a drug craving occurs, the amygdala becomes active and a craving for cocaine is triggered.

So if it’s the middle of the night, raining, snowing, it doesn’t matter. This craving demands the drug immediately. Rational thoughts are dismissed by the uncontrollable desire for drugs. At this point, a basic change has occurred in the brain. The person is no longer in control. This changed brain makes it almost impossible for drug addicts to stay drug-free without professional help. Because addiction is a brain disease.

This page was last updated January 2007

NIDA Publications

NIDA Notes: The Latest in Drug Abuse Research

Teaching Packets

Explores the consequences of drug abuse on the brain and body and introduces the topics of prevention, and treatment.