A widely prescribed antidepressant makes pubescent teens who are seriously depressed more likely to commit suicide, the health ministry and industry officials said Monday.

The Health, Labor and Welfare Ministry has ordered the importer of the drug to put warnings on its packages against administering the drug to seriously depressed people aged under 18, the officials said. But because a sudden halt in the drug's use can cause perception disorders, the ministry has called for a gradual reduction.

The drug, imported and sold by GlaxoSmithKline K.K., the Japanese subsidiary of GlaxoSmithKline PLC of Britain, carries the product name Paxil and is often prescribed by doctors in Japan as their first choice for treating depression.

After running clinical tests on children aged between 7 and 18, GlaxoSmithKline found that the risk of seriously depressed patients contemplating or planning suicide almost doubles after they take the antidepressant.

The tests, conducted on more than 1,000 children in Britain, did not confirm that the drug had a remedial effect on patient's depression, they said.

Of 378 young patients who were prescribed the drug, 5.3 percent began to consider or plan suicide, compared with only 2.8 percent of 285 patients dosed with placebos.

Paxil is one of a new type of antidepressant called selective serotonin reuptake inhibitors, which are touted as having relatively few side effects.

The ministry approved the product in 2000 for use by people aged 15 or older. The drug has since been given to 470,000 people a year.