BEHAVIOR OF RATS, COCAINE AND ADDICTION MYSTERIES

Cocaine is indisputably addictive, but while many fall into its hold,
others simply dabble and move on. To date, predicting how a user will
react to the drug has been anyone's guess.

A new study, however, suggests that one sign of the future addict is
plunging headlong into cocaine use from the very beginning.

Researchers at Yale reached that conclusion after studying rats that
were allowed to administer cocaine to themselves. They published their
findings in the journal Neuropsychopharmacology.

Dr. David W. Self, an associate professor of psychology, said he and
his colleagues had wanted to test two hypotheses about cocaine
addiction: that it was more prevalent among animals inclined to seek
novelty, or among those that are more sensitized to cocaine.

Neither turned out to be true, it appeared. Instead, the best
predictor of addiction seemed to be the amount the rats took in an
early part of the study, when they were allowed to dose themselves for
10 days.

All the rats in the study were then cut off from the drug, and their
degree of addiction was measured by how frequently they returned to
the cocaine dispensers.

The rats that used the most cocaine, about 35 percent of the group,
were the most likely to show signs of strong addiction.

Researchers suspect a possible biological basis for the
differences.

Dr. Self said the research could lead to a better understanding of why
some people are prone to drug addictions.

"A lot of people try drugs, but only some of them become addicted."