Antidepressants ... may be no better than dummy pills for people with mild or moderate depression, according to a study that suggests 70 percent of patients wouldn't benefit from the drugs. In a review of six trials of antidepressants involving more than 700 patients published yesterday in the Journal of the American Medical Association, researchers led by Jay Fournier at the University of Pennsylvania found the drugs helped only those patients with the most severe depression. Doctors, policy makers and sufferers should be made aware that there's little evidence to show the treatments will benefit patients with less severe symptoms, the authors said. This important feature of the evidence base is not reflected in the implicit messages present in the marketing of these medications to clinicians and the public," they said. The researchers combined data from six trials. The drugs had a "nonexistent to negligible" effect on patients with mild, moderate and severe symptoms, compared with those who took a placebo, according to a commonly used scale used to measure the disorder. The pills had a large effect on patients with very severe symptoms, the study found.