Yet when these formerly addicted rats were then given a single hit of cocaine, the tolerance of their dopamine transporters to the inhibiting effects of the drug was fully reinstated. This was also reflected in the way that they didn’t show any of the frantic behavior of other rats that were taking cocaine for the first time, as well as the way that these rats began to seek out the drug just as they had when they were addicted previously.
Summing up this finding in a statement, study co-author Sara Jones explained that “even after 60 days of abstinence, which is roughly equivalent to four years in humans, it only took a single dose of cocaine to put the rats back to square one with regard to its’ dopamine system and tolerance levels, and increased the likelihood of binging again,” sending them back to “that terrible cycle of addiction.”
Based on this discovery, the researchers believe that cocaine addiction “leaves a long-lasting imprint on the dopamine system”, which remains “primed” to respond to the drug when it encounters it again in the future.
This largely explains why so many addicts tend to relapse so spectacularly as soon as they give in to that little voice telling them that “one line can’t hurt”. On the positive side, though, it also highlights a possible avenue for the development of new addiction treatments, suggesting that medications that act on dopamine transporter sites could help to attenuate binge-like behaviors.
If you're a recovering cocaine addict, one line really can hurt. Jan H Andersen/Shutterstock