SHANGHAI, June 7 -- NERVOUS parents are seeking controlled stimulants to help their child sit the annual college entrance exams from today, city doctors say.

Doctors at Ruijin Hospital's youth psychological consultation center said four or five parents in the past month have asked for a medicine called Ritalin to help their child achieve higher marks.

Ritalin is a psychomotor stimulant on the central nervous system, usually used to treat children with attention deficit and hyperactivity disorders.

"All parents' requests for Ritalin were turned down," said Jin Wuguan, the center director, adding that only sick children could be treated with this medicine.

But some parents didn't give up that easily.

The Youth Daily reported that some parents asked their colleagues whose children used to have hyperactivity problems to ask for the medicine.

One mother was reported to have taken her son, who had already recovered from the disorder, to hospital four times within a month to ask for the medicine, which was all distributed to colleagues.

Other parents turned to sellers who advertised Ritalin over the Internet.

A Guangzhou-based seller surnamed Chen told Shanghai Daily that about 50 parents had called to asked for the medicine, priced at 400 yuan (US$52) for 100 tablets, in the past month.

"It is useful and no side effects would occur," said Chen, claiming that the medicine comes directly from a pharmaceutical factory in Suzhou, in neighboring Jiangsu Province.

But doctors have warned of possible side effects.

"The drug abuse might cause stomach problems and even paralysis," Jin said, adding that parents shouldn't pursue good scores at the expense of their child's health.

Although some parents are aware of the harm, they still choose to run the risk.

"I don't want to see my child lag behind others even though it's a bit risky to have the medicine," said a mother surnamed Liu. "I used to hesitate, but now getting a high score is the top priority."