NEW YORK (CNN/Money) - New, widely prescribed antipsychotic drugs are 10 times more expensive but no more effective than an older, discontinued drug, a news report said Tuesday.

A federally funded study that tracked patients for 18 months shows the influence that self-interested research by drugmakers can have on physicians, patients and policy-makers, the Washington Post reported.

Thomas Insel, director of the National Institute of Mental Health, which funded the $44 million study, told the Post it was "the largest, longest and most comprehensive independent trial ever done to examine existing therapies" for schizophrenia, which affects 3.2 million Americans.

The study compared an older generic drug, perphenazine, with newer antipsychotic drugs like Zyprexa from Eli Lilly & Co. (up $0.01 to $54.77, Research), Seroquel from AstraZeneca Pharmaceuticals (down $0.52 to $47.28, Research), Risperdal from Johnson & Johnson (up $0.02 to $64.67, Research), and Geodon from Pfizer (down $0.01 to $25.59, Research), according to the report.

The study will be published in the New England Journal of Medicine, the newspaper said.

To read about Lilly's patent battle over Zyprexa, click here.