快猫短视频

DOES giving hyperactive children the drug Ritalin make them more likely to
abuse cocaine, as some claim? No, suggests the latest study鈥攊t may
actually do the opposite. But the strength of the deterrent effect may vary with
the age at which it is taken.

The findings, based on experiments done with rats, add yet another twist to
the debate over Ritalin鈥檚 effects
(快猫短视频, 18 April 1998, p 18). 鈥淚t
raises interesting questions,鈥� says Alan Zametkin, a psychiatrist at the
National Institute of Mental Health near Washington DC. But he says it鈥檚 not
clear whether the findings apply to the millions of children given Ritalin.

Rats normally develop a preference for places where they鈥檝e been given
cocaine. But Susan Andersen鈥檚 team at Harvard Medical School found that rats
treated with Ritalin before puberty avoided a chamber where they had received a
moderate dose of cocaine. Rats given Ritalin as adults were indifferent to the
place.

The team found parallel changes in gene expression in a brain region thought
to mediate the rewards associated with cocaine. The findings show that
psychostimulants cause changes in the brain that persist long after the drug has
been used, says Cindy Brandon of Finch University of Health Sciences in Chicago.