Scientists have identified a gene linked to heroin addiction and blocked it in rats, eliminating their jones. Ivan Diamond of the Ernest Gallo Clinic and Research Center believes it could lead to a treatment for humans within a few years. From New Scientist:
Heroin-addicted rats that were trained to give themselves the drug using a lever were injected with the AGS3 blocker into their nucleus accumbens after they had gone through a short period of withdrawal. A small dose of heroin then was administered to each rat.
Normally even such a tiny "taste" of the drug leads to cravings for more, but the blocker prevented the addiction relapse by eliminating these desires. The treatment produced no other observed behavioural side effects.