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Ketamine could reduce harmful drinking by ‘rewriting’ memories
A single ketamine infusion could help heavy drinkers reduce their alcohol consumption by altering reward memories associated with alcohol, according to a study published in Nature Communications.
“Learning is at the heart of why people become addicted to drugs or alcohol,” Ravi K. Das, PhD, MSc, associate professor of education psychology research methods and statistics at University College London, said in a press release. “Essentially, the drug hijacks the brain’s in-built reward-learning system, so that you end up associating environmental ‘triggers’ with the drug. These produce an exaggerated desire to take the drug.”
“Unfortunately, once these reward memories are established, it's very difficult to re-learn more healthy associations, but it's vital in order to prevent relapse,” he explained.
To “rewrite” reward memories, Das and colleagues gave participants a beer and told them they could have it once they completed a task. To retrieve reward memories tied to alcohol consumption, they were shown images of beer, orange juice and other alcoholic and nonalcoholic drinks and asked to rate the pleasure they would get from consuming the beverages.
On the first day, participants were allowed to drink the beer after completing this task, but it was taken away from them unexpectedly on the second day, destabilizing their reward memory.
A third of participants were then given an infusion of ketamine, which prevented the reward memory associated with alcohol from being re-stabilized by the brain. Another group of participants were given placebo instead of ketamine, and others were given ketamine without completing the task to retrieve alcohol-related reward memories.
The 90 participants included in the study were heavy drinkers who were not diagnosed or treated for alcohol use disorder. At baseline, participants drank an average of 74 U.K. units of alcohol — approximately 30 pints of a beer — each week, which is five times the recommended limit, according to the release. All participants indicated that they preferred beer to other alcoholic drinks.
After 10 days, patients who completed memory retrieval and received ketamine demonstrated significant reductions in their desire to drink, consumed less alcohol and drank on fewer days compared with those in the other two groups.
During 9 months of follow-up, the two groups of participants who received ketamine had statistically significant reductions in the amount of alcohol they drank. However, only those who had their memories retrieved before receiving ketamine had significant reductions in drinking days and binge drinking.
At the end of follow up, those who underwent memory retrieval and received ketamine cut their weekly alcohol consumption in half.
“This is a first demonstration of a very simple, accessible approach, so we hope that with more research into optimizing the method, this could be turned into a helpful treatment for excessive drinking, or potentially for other drug addictions,” Das said. – by Erin Michael
Disclosures: The authors report no relevant financial disclosures.