The idea of erasing people's memories sounds like something straight from the script of Men In Black, but what if those memories are damaging ones - like knowledge of an addiction to a harmful substance? Researchers in the US are testing a drug that they say can effectively wipe away memories of a meth addiction in the brains of laboratory mice.

For drug addicts attending rehab and trying to stay clean, that could have a big impact. The newly developed drug works by targeting memories associated with methamphetamine use: these particular memories can be targeted because they're created differently to normal, not-high-on-drugs memories. A protein called actin helps stabilise memories in our brain, but in the case of memories created during meth use, that actin scaffold is never fully fixed in place - and the scientists' big achievement is being able to focus on those memories alone.

Because actin is important in other areas of the body, it can't simply be marked for removal. Instead, the team from the University of Florida targeted the non-muscle myosin IIB molecule - this helps actin work but is further up the biological ladder. By disrupting the non-muscle myosin IIB, the memory's foundation crumbles, and the mice forget all about their trip, and the feelings associated with it.

What works on mice won't necessarily work on humans, so there's a lot more investigation to be done, but it's a promising development. "What is particularly exciting is that myosin only has to be inhibited once," neuroscientist and study author Courtney A. Miller told The Washington Post. "The effect lasted as long as we tested the animals. I hesitate to use the word 'erased', but the memory seems to be gone."

No matter how effective the treatment for drug addiction, the chance of a relapse never goes away - a certain sight, smell or feeling can trigger something in the brain that causes an addict to revert to his or her earlier behaviour. The hope is that this new way of tackling the problem could provide a lasting escape from dangerous drug use.

"Approximately one to three months into recovery, many abstinent individuals report hitting a 'wall'. This phase of recovery is marked by anhedonia [the inability to feel pleasure] and strong cravings that often result in relapse," adds Miller. "[Our idea] is that someone would go into a rehab program with the typical abstinence therapies and while they are in the treatment program they would receive this medication one time and it should remove all of the associations with the drug."

The study has been published in Molecular Psychiatry. The next challenge is testing how the medication works with other drug addictions besides meth, and checking its reaction to other types of treatments, before finally attempting to make it safe for human use.