Addiction and the brain: The dopamine pathway is helping researchers find their way through the addiction maze

Extract

Our flourishing knowledge of the brain is in large part the product of research on addiction. Identifying what happens in the brain when a drug is inhaled, injected, or eaten, why it leads to compulsive drug seeking, and learning how to disrupt that process has seemed like the last best hope for a permanent fix for addiction. Which is why, according to Alan Leshner, director of the National Institute on Drug Abuse (NIDA), researchers know more about drugs in the brain than they know about anything else in the brain.

Among the revelations: addiction is now seen to be a brain disease triggered by frequent use of drugs that change the biochemistry and anatomy of neurons and alter the way they work. Scientists have developed a basic model of addiction that presents these changes as the desperate attempt of the brain to carry on business-as-usual—to make neurons less responsive to the drugs and so restore homeostasis—while under extreme chemical siege.