Can Brain Chemistry Lead to Alcoholism?

Research professor's findings suggest neurochemical mechanisms play important role in alcoholism

Two Scripps researchers review back lit images of brain scans as part of a study linking brain chemistry to alcohol addiction.

Why does 10 percent to 15 percent of the population become alcoholic and the rest of the population does not?

This is the question George F. Koob, neuropharmacology professor at The Scripps Research Institute (TSRI), seeks to answer. Professor Koob has been studying the neurobiology of alcohol and alcoholism for the past several years and has developed models of normal and excessive drinking to study alcohol’s effect on the brain.

According to his findings, specific neurochemical mechanisms in certain areas of the brain may hold the key.

In 2001, the National Institute on Alcohol Abuse and Alcoholism (NIAAA) funded a multiyear consortium headed by Koob to identify the molecular basis of alcoholism. The aim of the Integrative Neuroscience Initiative on Alcoholism grant is to address the basic science of alcoholism and to establish a platform upon which future treatments can be developed.

“The goal is to figure out what makes people vulnerable to excessive drinking,” says Koob. “What is the genetic loading and how does that interact with environmental determinants?”

Scientists now know that there are particular cells in the brain that alcohol targets. And Koob’s research has identified several neurobiologic mechanisms involved in the development of alcoholism. His studies using animal models show that during the development of alcoholism, multiple neurotransmitters in various parts of the brain combine to make the consumption of small amounts of alcohol enjoyable.

“Alcohol tends to activate the whole brain reward system,” Koob explains.

Additionally, Koob’s research implicates the brain’s stress system in alcohol dependence. The major component of the brain stress system is corticotropin-releasing factor or CRF. Koob’s studies indicate that certain individuals are at increased risk of becoming alcoholics perhaps because their genetic makeup causes them to have higher than normal levels of activity in the CRF stress system.

“They may be drinking to feel normal — they may drink to tame a hyperactive CRF stress system in the brain,” he says.

Searching for solutions for addiction

The goal of much of Koob’s work is to someday help individuals who have become addicted to alcohol.

“It’s very possible that we’re are going to find brain areas that code for certain proteins responsible for the individual differences that make 15 percent of the population vulnerable to alcoholism and/or that protect 85 percent,” Koob asserts. “Once we know the circuits and the basis for alcoholism, we can develop new targeted treatments.”

The Scripps McDonald Center, which provides treatment programs for drug and alcohol abuse, has been following Dr. Koob’s research with keen interest.

“In the future, there will be much better assessment, treatment and outcomes, based on being able to take into account a patient’s genetic marker,” says Tom Brown, Ph.D., administrative director of the center.

Koob’s findings on the neurobiology of alcoholism were published in the February issue of Alcoholism: Clinical and Experimental Research, the journal of the Research Society of Alcoholism.