Your Brain on Alcohol
A new understanding of how alcohol alters brain chemistry may transform treatment of the disease
Once excessive drinking begins, the new research shows, alcohol begins resculpting the brain regardless of family history. "In even nonsusceptible individuals, chronic use may create addiction," says psychiatrist Raymond Anton, scientific director of the Charleston Alcohol Research Center at the Medical University of South Carolina. People who binge several times a week--five or more drinks in a day for a man, four or more for a woman, according to the National Institute on Alcohol Abuse and Alcoholism--are clearly at risk, and they can also suffer other consequences like impaired concentration, slowed reflexes, disrupted sleep, and high blood pressure. There's no evidence, however, that moderate drinking--two drinks a day for men, one drink for women--alters brain chemistry.
Want becomes need. People often start down the road to alcoholism in their teens or 20s. But stress later in life--a divorce in their 30s, a job loss in the 40s, the death of a loved one anytime--can also push a life off course. At this point, the amygdala, the part of the brain that helps the body respond to stress, may be calmed by alcohol. But though these drinkers may start later in life, heavy drinking likely causes similar brain alterations. Barbara Halsey, 47, didn't begin to drink heavily until she divorced in her early 30s. At first, it was for the relief and fun of partying. Pretty soon, she was drinking almost every night. "I'd stay out late. I found myself losing jobs," she says. However it starts, heavy drinking eventually robs alcohol of its value as a brain treat. Want becomes need. The drinker needs ever more alcohol to provide the same high until, eventually, the high is gone. "There was a time in my life when chemicals did something for me. And then one magical day, they stopped," says Jay Ehrlich, who has been sober for 16 years. "And I spent an inordinate amount of time trying to cross back over and get it back."
At this point, recent brain-imaging studies show, the primitive nucleus accumbens, with its hunger for pleasure, may ultimately not be the main player. New pathways have been formed, adapted to function in alcohol's service. Now, researchers believe, the frontal cortex, the brain's executive branch responsible for decisions and memory, holds a mere memory of pleasure, as insistent as the original pleasure, and demands another drink. Alcohol may also put its stamp on areas of the frontal cortex involved in judgment and impulse control.
From the frontal cortex, it's a short hop to the basal ganglia, the brain center that when wired differently makes obsessive-compulsive people continually wash their hands or avoid stepping on cracks. The latest results from laboratory-animal studies suggest that alcoholism may use the same neural pathways that lead to compulsive behaviors. The brain then demands more and more alcohol, regardless of reason and consequences. "In the end, I'd drink by myself. I'd hide beer in the closets, under the porch of the house. It wasn't fun anymore. It went from a luxury to a must," says Michael Small, 40, of Zephyrhills, Fla., who drank for more than 20 years before entering treatment.
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