By modifying memories of past drug use, scientists have found a new way to help ex-drug addicts avoid relapsing.
Similar strategies already exist, but this one doesn’t involve using memory-blocking drugs.
The concept is called ‘extinction,’ and it involves exposing ex-addicts to cues that typically trigger drug cravings – such as the sights, sounds, and smells experienced while using drugs (and in particular, the paraphernalia and usual surroundings). Being sober during the extinction procedure allows the patient to gradually become less and less sensitive to these cues. But the benefits wear off, and researchers have tried to boost the effect by using memory-altering drugs (in rats, since its not approved for our use).
Building on that concept, Lin Lu of the National Institute of Drug Dependence at Peking University in Beijing and his colleagues found a way to strengthen extinction in rats and decrease drug cravings in humans. And they’ve done so through behavioral intervention only.
They briefly reactivated the memory of drug taking and followed it with an extinction session of repeated exposure to the same memory cues, Nature explains. And that short reminder of drug-taking seems to take the memory out of storage and make it easier to overwrite.
- Volunteers who had undergone detox after heroin addiction were exposed to a brief reminder of past drug use to retrieve memories from the longterm storage in their brains: a 5-minute video of images of heroin use and drug paraphernalia.
- Within an hour of that quick reminder, the subjects went through a much longer extinction procedure: an hour-long session with repeated images.
Individuals who had gone through this combination intervention were less likely to resume using or craving drugs in response to reminders of their former drug use – compared to individuals who had gone through extinction alone.
In fact, addicts who were shown the video 10 minutes before the extinction session showed decreased drug cravings up to 6 months later.
Turns out, this intervention involves a process called ‘memory reconsolidation,’ where an experience (of getting high, for example) is recalled from longterm memory and – by erasing the link between drug taking cues and getting high – it is altered before it reenters long-term storage.
The study was published in Science this week.
[Via Nature News]
Image by Amber Wilkie via Flickr