Cocaine addicts are known for being frenetic, but which came first, the behavior or the habit? New research indicates that, at least in rats, it's the behavior that begets addiction.  Also, the study has pinpointed the character trait- impulsiveness- that is responsible for developing true drug dependence.
    Scientists who study drug addiction have a common problem: The individuals they deal with are already addicted, so it's hard to tell what, if any, behaviors led to the initial dependence.  What they do know is that two traits: impulsiveness and thrill-seeking tend to define most drug addicts.  Apparently the experiment determined that impulsivity actually leads to addiction.  Thrill-seeking individuals tend to use the drug for a period of time, then become bored, apparently when the thrill is over.
    So, knowing this, we can identify individuals at early times in their lives that may be prone to developing an addiction.  And its shown that anti-impulsivity medication, such as some antidepressants, may be the key to helping people stay away from cocaine for good.

This is kind of like addictive personalities, whether people are more prone to become dependant on something, it doesn't always have to be drugs.  Thrill-seekers are probably more likely to try drugs, that makes sense.  My brother is sort of like that, he's always ahead of trends, always trying the newest thing.