British researchers say that impulsivity seems to trigger
addiction and not the other way around, Science magazine
reported June 6. People with addictions are known to be more
impulsive and engage in more thrill-seeking behaviors than non-
addicts, but it has been unclear whether those behaviors
predated drug use or were the result of addiction. Researchers
David Belin and Barry Everitt of the University of Cambridge
attempted to answer the question by studying rats known to have
thrill-seeking or impulsive personalities. The researchers
connected the rats to a device that delivered cocaine directly
to their brains and then gave the rats control over their drug
use. They found that the thrill-seeking rats tried the drug
immediately and in high doses, while the impulsive rats used the
drug less quickly and in greater moderation. However, the
authors found that after 40 days of access to the drug the
impulsive rats had become addicted and could not stop using
cocaine even when punished with an electric shock, wh