Alcohol Targets Brain 'Reward Centers' in Heavy Drinkers
WEDNESDAY, Jan. 11 (HealthDay News) -- A small study that offers new insight into how alcohol affects the brain could help lead to more effective treatments for people with drinking problems.
Researchers used positron emission tomography (PET) imaging to observe the effects of alcohol in the brains of 13 heavy drinkers and a control group of 12 people who were not heavy drinkers.
In all of the participants, drinking alcohol triggered the release of endorphins in areas of the brain [the nucleus accumbens and orbitofrontal cortex] that produce feelings of pleasure and reward. Endorphins are proteins that are produced naturally in the brain and have opiate-like effects.
The more endorphins released in the nucleus accumbens, the greater the feelings of pleasure reported by people in both groups. Among heavy drinkers, the more endorphins released in the orbitofrontal cortex, the greater the feelings of intoxication. This did not occur among people in the control group, the researchers found.
The study is published in the Jan. 11 issue of the journal Science Translational Medicine.
This is the first time that the release of endorphins in these two brain areas after drinking alcohol has been observed in humans, said the researchers at the Ernest Gallo Clinic and Research Center at the University of California, San Francisco (UCSF).
"This is something that we've speculated about for 30 years, based on animal studies, but haven't observed in humans until now," lead author Jennifer Mitchell, clinical project director at the Gallo Center and an adjunct assistant professor of neurology at UCSF, said in a university news release. "It provides the first direct evidence of how alcohol makes people feel good."
Pinpointing the exact locations in the brain where endorphins are released could lead to the development of more effective drugs to treat alcohol abuse, the study authors suggested.
The findings show "that the brains of heavy or problem drinkers are changed in a way that makes them more likely to find alcohol pleasant, and may be a clue to how problem drinking develops in the first place," Mitchell said. "That greater feeling of reward might cause them to drink too much."
The U.S. National Institute on Alcohol Abuse and Alcoholism has more about alcohol abuse and alcoholism.
SOURCES: University of California, San Francisco, news release, Jan. 10, 2012
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