Leading medical journal the Lancethas urged GlaxoSmithKline to reveal all its research on the antidepressant Seroxat.
The drug has been the subject of controversy because of a possible increased risk of suicidal behaviour in young patients.
New York Attorney General Eliot Spitzer filed a suit last week, claiming Europe's largest drugmaker withheld negative information about treating children and teenagers with the drug, which is also known as paroxetine and sold in the United States under the name Paxil.
Glaxo has denied the allegations and says it had acted responsibly.
But in an editorial, the Lancetsaid the company had sponsored at least five studies that tested the drug's efficacy in children but only one, which had mixed results, has been published.
"If GSK has nothing to hide, as it claims, it should open the files before being ordered to do so by a court - and do so right now," the journal said.
It added that the disclosure of the results had been limited to the Federal Drug Agency in the United States and other regulatory agencies, but that doctors and consumers needed the information to make informed decisions.
"But as the lawsuit pointedly demonstrates, the time has come for these matters to be revealed in a bright and public light," the journal added.
Mr Spitzer, who filed the suit in the New York State Supreme Court in Manhattan, demands Glaxo give up all profits from the sale of the drug in New York for treating depression in children and teens. The suit also seeks unspecified damages.