All in the Mind

Article excerpt

With a new $1.42 million federal grant to study cocaine addiction in hand, Dr. WenLin Sun would like to drive home one point that science has nailed down: Chronic drug addiction is a brain disease.

"That's one of the achievements in the past 20 or 30 years," said Sun, an assistant professor in the Department of Pharmacology at the University of Tennessee Health Science Center. "There is overwhelming evidence that drug addiction is a brain disorder."

That goes for addictive drugs that range from nicotine, alcohol and marijuana to cocaine, heroin and methamphetamine, he said.

The National Institute on Drug Abuse of the National Institutes of Health has awarded $285,000 over five years for Sun's latest research. A key feature of drug addiction is that people continue their drug-seeking and drug-taking behavior despite devastating consequences such as losing a job, custody of children, a spouse and landing in jail.

"What I'm trying to understand is why drug addicts are insensitive to those devastating consequences," he said.

The technical project title is "Cocaine Addiction: Neuropharmacological Mechanisms of Compulsive Cocaine Use."

Sun, who uses rats hooked on cocaine for his studies, said evidence points to an area in the middle brain where dopamine, a chemical that nerve cells use to transmit signals, is released.

Chronic drug addiction results in profound changes to brain structures that play a critical role in motivation, learning and memory, he said. …