Patterns: Study Finds Problem Drinkers Get Bigger Endorphin Kick
Nicholas Bakalar - New York Times 12 January 2012
Drinking alcohol causes a pleasant feeling because it releases endorphins, the brain’s natural opioids. But a new study has found that problem drinkers differ from social drinkers in the way alcohol affects one part of the brain. The report appeared Wednesday in Science Translational Medicine.
Researchers performed PET imaging on 13 heavy drinkers and 12 social drinkers after each had had a standardized amount of alcohol. The scientists traced the release of endorphins in two regions of the brain — the nucleus accumbens and the orbitofrontal cortex — and recorded the volunteers’ subjective feelings of intoxication.
All subjects reported feelings of intoxication as the researchers observed changes in opioid release in the nucleus accumbens. There was no difference between heavy drinkers and the control group when it came to changes in blood alcohol levels over time.
But with the heavy drinkers, unlike with the healthy controls, there was a positive correlation between the release of endorphins in the orbitofrontal cortex and the subjects’ subjective feeling of drunkenness.
This phenomenon, the authors write, may contribute to an increased perception of pleasure and to excessive alcohol consumption in these drinkers.
The lead author, Jennifer M. Mitchell, a neuroscientist at the University of California, San Francisco, said that her aim is to find better ways to treat alcoholism. “There’s an interesting relationship between endorphin release and problem drinking,” she said. “By understanding where the endorphin release occurs, and which receptors it binds to, we can make a better drug.”