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."
More information
The U.S. National Institute on Alcohol Abuse and Alcoholism has
more about
alcohol abuse and alcoholism.