Adjusting a key brain receptor could control binge drinking

April 17 (UPI) -- Deactivation of a stress-signaling system in the brain, the opioid receptor system, can decrease binge drinking, scientists at the Medical University of South Carolina say, according to a study published in the May edition of Neuropharmacology.

Binge-drinking is scientifically defined by the National Institute on Alcohol Abuse and Alcoholism as drinking to the legal limit of intoxication within two hours.

One in six U.S. adults binge drinks about four times per month, consuming about seven drinks per binge, the Centers for Disease Control and Prevention says, adding that the practice is most common among those age 18 to 35.

Those who consistently binge drink, particularly during adolescent and college years, have almost 10 times the risk of developing an alcohol use disorder, said Howard Becker, research leader and co-author of the study.

"Through our investigation, we found a brain region and a system that we can manipulate to decrease binge drinking," study co-author J.R. Haun said in a press release.

The opioid receptor system is well-recognized in the addiction field. Morphine, heroin, oxycontin and oxycodone act on system to produce the pleasurable effects that making the drugs addictive. One receptor in the system, though, called the kappa, produces discontent and is activated during the stress of hangovers and withdrawal.

"The kappa opioid-receptor system is the antithesis to other opioid receptors," explained Haun. "It's often referred to as an anti-reward system."

The researchers, using binge drinking mice as test subjects, studied the extended amygdala, a part of the brain involved in motivational behavior and containing significant kappa opioid receptors. Using a drug, they inactivated the kappa opioid receptors.

"Haun actually introduced a drug that blocks kappa opioid receptors right into the extended amygdala," explained Becker, which resulted in diminished voluntary alcohol consumption. The study indicates that blocking the kappa opioid receptors could be part of therapy to reduce binge drinking.

The study suggests the urge to binge drink could also eventually be controlled through medication, the researchers said.

"I think the ultimate goal is to better understand new potential treatment targets and how new therapeutics may have some value in helping to quell the desire and motivation to drink excessively in those who have developed an alcohol use disorder or are on the threshold of doing so," Becker said.