Chinese scientists ‘erase’ drug memories in heroin addicts

Scientists have found a way to ‘erase’ drug-related memories to help to curb cravings for heroin addicts, according to a new study.

The researchers at Peking University in China used a procedure called memory retrieval-extinction alongside methadone treatments to effectively reprogram the brains of addicts.

Memory retrieval-extinction is based on the premise of basic conditioning training, meaning that by repeating a certain stimulus – in this case, a drug – coupled with a signal, memories of that stimulus can be ‘reopened’ to be changed and even erased.

In this study, however, they use a small simulation of the high – by administering methadone – as the stimulus to re-open and reprogram memories of addiction in the minds of addicts. 

Researchers in China found that a small dose of methadone coupled with a memory manipulation technique can help reduce cravings and relapse for heroin addicts

The researchers in this study rely on the way that memories are formed to rewrite them in drug addicts. 

Memory formation is ‘a dynamic process with different stages,’ lead study author Dr Ping Wu said in her presentation at the Society for Neuroscience conference.

After we take in sensory information – sights, sounds, smells, tastes and tactile information – that will become the content of the memory, there is a period of consolidation, when that information is being encoded into the brain. 

Consolidation can take as little as ten minutes, but by the time six hours have gone by, the memory is thoroughly formed, and difficult to tamper with. 

For addicts, memories of doing their drug of choice come with a series of associated stimuli. There is the high itself, accompanied by paraphernalia and other environmental factors that the brain has consolidated into a drug memory. 

Each time these stimuli are repeated, the memory is opened and then reconsolidated, to make it even more robust. 

Previous research in animals, however, has shown that by ‘cuing’ the memory of a drug high, the memories that lead to cravings can be tampered with and manipulated. 

In rats, researchers have found that just reintroducing light or sound cues they had trained the animals to associate with a drug high could re-open these memories. During that window of time, the researchers did not let the rats have the drugs – cocaine or heroin – and found that this reduced their drug-seeking behavior, or cravings, even after the six-hour reconsolidation period. 

But simply using the associated cues did not work as well for humans addicted to heroin. 

So Dr Wu and her team in China tried triggering the drug memory with a very low dose of methadone, which is used both as a treatment for pain and for weaning recovering addicts off of heroin or other opioids, and then ‘extinguished’ or erased the memory of the high simply by not allowing the subject to have more heroin to induce it. 

‘The use of this procedure significantly increased the disruption of the addiction memories associated with the conditioned stimuli… 10 minutes and six hours after the methadone was given,’ Dr Wu said. 

‘Using methadone as part of a memory treatment strategy may be a promising method for decreasing long-term drug cravings and relapses in heroin addicts,’ she added.

Read more at DailyMail.co.uk