Prozac Makes Rats Assertive

Prozac, an anti-depressant drug used widely to treat personality disorders, causes rats to challenge the authority of "boss" rats, a study published in the New Scientist magazine last week said.

Scientists at Rockefeller University in New York found the drug caused subordinate males to become more assertive although they did not become aggressive. Rats usually organize themselves into complex social structures in which one male rat is dominant and keeps the others away from his feeding and water areas. But subordinate rats given Prozac resisted the boss rat, according to the study.

"The drug is said to give people more self-esteem," said Christina McKittrick, who worked on the study. "The rats, too, seem to have more confidence. They're not trying to take over but they're saying: `I'm not backing down. I'm not putting up with this crap any more.' "