It takes a supreme effort of will to overcome an addiction, but even more so to avoid relapse. The effect of relapse can hugely effect quality of life or even prove fatal.To help give recovering addicts a fighting chance, researchers at University of Washington have been studying whether changing the activity of neurons in the nucleus accumbens, the region of the brain that regulates addictive behaviour, can help to prevent relapse.They achieved this targeted change in brain activity using chemogenetic receptors in a study conducted on rats who had been exposed to heroin.