Long before I began working in residential addiction treatment programs, I spent much of my career in hospitals and community-based treatment settings. In working with disadvantaged populations in community treatment programs, it became clear to me that only limited improvement can be achieved with medication alone.

There are many changes in people’s brains and behaviors that must take place for them to lead fulfilling lives.

Despite a growing body of neuroscientific research, we have yet to develop effective new treatments for addiction. Addiction is indeed a biological disease, but it is also a behavioral and spiritual one. As a result, modern medicine’s focus on developing new medications to treat addiction has fallen short.

Fortunately, some researchers are beginning to explore behavioral mechanisms that may fill in some of the gaps in addiction treatment. In a study published this month in Science, researchers from the National Institute of Drug Dependence at Peking University used a behavioral procedure to manipulate addicts’ memories of past drug-taking that shows promise in reducing drug cravings and preventing relapse.

Unlearning the Cue-Craving Association

Although we are able to manage drug cravings during treatment, it is still common for recovering addicts to relapse once they return to their home environment, surrounded by familiar reminders that trigger the urge to use. It is believed that these triggers result from classical conditioning (think of Pavlov’s famous experiment where dogs were given food every time a bell rang, which eventually caused them to salivate when they heard the bell regardless of whether food was present.)

Like Pavlov’s dogs, recovering addicts associate certain cues with the euphoria of drug use so that being exposed to these cues triggers powerful drug cravings.

As Pavlov discovered 100 years ago, classical conditioning can be undone. If the dogs heard the bell a number of times without receiving food, they un-learned the association. This process, known as “extinction,” may be used to help addicts “forget” the association between certain cues and drug use.

The process appears to be particularly effective when the memory is reactivated (with a brief reminder of drug-taking, such as watching a video of drug use or holding a needle) and then overwritten through repeated exposure to the same cues without subsequent drug use. This type of memory reconsolidation relies on the theory that there is a brief window of time after a memory is accessed during which it can be “rewritten.”

Previous studies by Liz Phelps and Joe LeDoux showed the process of memory reconsolidation could weaken fear memories in both rats and humans. Building on their model (in which participants were repeatedly shown a blue square while receiving mild electric shocks on the wrist), the Peking University researchers showed recovering addicts a video depicting drug use and interviewed them about their drug cravings.

One group was shown the video 10 minutes earlier, to trigger reconsolidation of the memory during the extinction training. The other group saw the video six hours before the extinction session.

What they discovered is that the old memory disappeared in the group that saw the video 10 minutes earlier and that the result was long-lasting (subjects reported that cravings were reduced up to six months later). It is believed that the brief exposure 10 minutes earlier reactivated the memory of drug taking, making it easier to override the association between drug use and getting high.

A Healthy Dose of Cautious Optimism

This research has clear limitations. So far, it has only been tested on rats and hospitalized heroin addicts, meaning it may not be effective outside of the clinical setting. The procedure needs more in-depth testing to assess potential side effects, investigate underlying neural mechanisms, and to determine its applicability to other drugs and disorders.

Still, this study represents an exciting non-pharmacological alternative to much of the research currently being conducted. Targeting memories, while not entirely new, could be an important addition to existing interventions.

David Sack, M.D.,  is board certified in Addiction Psychiatry and Addiction Medicine. He is CEO of Elements Behavioral Health, a network of treatment centers focused on addiction and mental health issues.

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    Last reviewed: 3 May 2012