Medications may not be needed to eliminate the drug-related memories that trigger relapse in addicts. Appropriately timed behavioral interventions may do the trick, according to new research published in Science.
Researchers have known for years that exposure to stimuli associated with past drug use — “people, places and things,” in the jargon of recovery programs — can elicit the desire to get high again. It’s similar to they way hearing “your song” may prompt alluring memories of that ex you vowed never to call again.
Scientists have also found that the seductive power of these drug-related cues can be extinguished if people are exposed to them repeatedly, but do not engage in their prior addictive behavior — something that’s hard to accomplish in real life. But the effects of this “extinction” process often wear off over time.
In rat studies, researchers have shown that specific drug-related memories can be zapped with a memory-destroying drug, without causing apparent damage to other memories. But this treatment requires brain surgery and the drug used is not safe for humans. So, Chinese researchers led by Yan-Xue Xue decided to see if there was another way.
They knew that when memories are consciously brought to mind, they are for a short period very fragile, vulnerable to being edited, rewritten or even possibly deleted entirely. Previous research has shown that associations between specific experiences and fear in both rats and humans can be eliminated without drugs during this reconsolidation period immediately after recall.
This is accomplished by simply recalling the feared experience briefly before exposure to a cue that is related to it; exposure to that cue is then repeated without triggering terror. For example, someone who has become afraid of dogs because of a bad experience might be prompted to recall that experience and then exposed repeatedly to dogs in extremely safe situations. Studies find that this technique works if the bad memory is recalled just before exposure to the scary cue — within 10 minutes to an hour — but not long before: there’s no effect if the experience is brought to mind six hours earlier.
Studying heroin addicts who had completed a detox program, the researchers found that it was more effective to expose the participants to drug-related videos 10 minutes before a training session in which they were again presented with drug paraphernalia but given no drugs than to simply conduct the trainings without prompting recall in advance or have them recall the memories six hours in advance of the training.
In a commentary published along with the new study, two Cambridge University researchers write:
Remarkably, the authors successfully [applied] the approach to a population of heroin addicts… Only the group that had the 10-minute delay between the heroin video and [training] showed a marked reduction in craving and blood pressure after presentation of heroin-related cues at every time point tested.
Unfortunately, cue-related craving is not the only thing that drives relapse in addiction so this will not be a “cure.” And the procedure must be done in a rehab or in another supportive situation, so that recalling cues doesn’t simply prompt immediate relapse. The technique could be a good addition to rehab practice, however — and it’s certainly less frightening and invasive than using drugs to zap problem memories.