St John's wort is as effective in treating depression as imipramine, a standard anti-depressant, according to the largest study yet of the herbal remedy. The British Medical Journal reports this week of the study carried out by German scientists at the University of Giessen. A total of 324 patients were randomly assigned to treatment with either hypericum extract (St. John's wort) in tablets or imipramine. Hypericum was better tolerated than imipramine and fewer patients on hypericum withdrew as a result of adverse effects. Researchers at the University said the herb should be considered as a first-line treatment for patients with mild to moderate depression.