British scientists are recruiting volunteers to test whether ketamine, also known as the party drug "Special K", may be helpful in reducing relapse rates among people with severe alcoholism.

After pilot studies that showed ketamine combined with psychotherapy might make detoxing alcoholics less likely to relapse, the scientists are looking for 96 volunteers with severe alcohol disorder who have been "recently abstinent".

Ketamine is a licensed medical drug, widely used as an anaesthetic and to relieve pain. But it is also used as a recreational drug and can lead some people into drug abuse.

"Ketamine is a well-tolerated drug and can help alleviate the symptoms of depression, with a pilot study suggesting that it could cut alcohol relapse rates by more than half," Celia Morgan, who will lead the research at Exeter University, said.

"This trial will allow us to examine whether ketamine, combined with therapy, can indeed help people stay abstinent from alcohol."

Half the participants will get a low-dose ketamine injection once a week for three weeks, and will also get seven 90-minute sessions of psychotherapy. A control group will get the same course of therapy, but with injections of saline solution.

Morgan's team will compare the results after six months using data collected via a device fitted to each participant's ankle that monitors alcohol intake by testing sweat.

More on this...

Research in mice has shown ketamine could prompt changes in the brain that make it easier for a person to make new connections and learn new things in the short-term. The researchers hope this could make the psychotherapy sessions more effective for alcoholics.

A pilot study found that three doses of ketamine plus psychotherapy reduced average 12-month relapse rates to 34 percent from 76 percent. Scientists think ketamine's antidepressant properties may have helped.

According to World Health Organization (WHO) figures, some 3.3 million people die each year from harmful use of alcohol, and alcohol abuse contributes to more than 200 diseases and conditions caused by injury.

"Alcoholism can have a terrible impact," said Kathryn Adcock, head of neurosciences and mental health at the Medical Research Council, which is jointly funding the study. "But current treatments ... are associated with high relapse rates - with people often return to drinking after only a short time."