"Antidepressant drugs really do work a major new international study has proven. Pooling data from  trials including nearly  patients researchers found all drugs analysed were more effective than placebos in the treatment of adults with acute depression. Authors of the studypublished yesterday in the Lancet http many more people could benefit from antidepressant medication. The study results represent the most comprehensive evidence currently available they wrote. In the international study published in the Lancet authors found that fluoxetinecommonly sold under then trade name Prozacwas one of the least effective antidepressants. Stephen CherninGetty Images  More than  million people worldwide have depression according to the World Health Organization http of which less than half recieve effective treatments. In many countries the rate drops to less than  percent. In the U.S. the National Institute of Mental Health estimates https . million adults experienced at least one major depressive episode in . Approximately  percent of these people received no treatment. In the U.K where a number of the study authors are based at least one million more people could benefit from drugs or psychotherapy senior author John Geddes said. Some drugs more effective than others The researchers analyzed existing studies of  different drugs and found some were much more effective than others. Drugs ranged from more than one third more effective than a placebo to more than twice as effective. The best performers included amitriptyline and escitalopram while the worst included fluoxetinecommonly sold under the trade name Prozacand reboxetine which is not approved for sale in the U.S. A complex treatment picture The results add up to a complex treatment picture for what authors called one of the most common burdensome and costly psychiatric disorders worldwide in adults. Antidepressants do not improve symptoms in about  percent of people study author Andrea Cipriani of Oxford University told a press briefing. While these results should reassure many people with depression that antidepressants can be effective this does not necessarily mean antidepressants should always be the first line of treatment he said. Talking therapies are thought to be about as effective as antidepressant medication but these are often much more expensive. Experts not involved in the research agreed the results were significant. Helen StokesLampard chair of the U.K.s Royal College of GPs expressed concern about the stigma surrounding antidepressant use. She said in a statement http Taking antidepressants is frequently portrayed as a negative thing or something done only when other therapies are not available or have failed but this in itself can add to the unfortunate stigma that sometimes exists around people with mental health conditions. But she also urged caution. Although antidepressants are of proven benefitas this study shows she said no doctor wants their patients to become reliant on medication. Putting a longheld controversy to bed Carmine Pariante a professor at the UKs Institute of Psychiatry Psychology and Neuroscience and spokesperson for the Royal College of Psychiatrists said the study finally puts to bed the controversy on antidepressants. James Warner an Imperial College London psychiatrist added Depression causes misery to countless thousands every year and this study adds to the existing evidence that effective treatments are available."