The BMJ’s new series of head-to-head debates has proved highly newsworthy. In the latest, two Australian psychiatrists clash over whether depression is over-diagnosed. , of the University of New South Wales, in Sydney, claims that the threshold for clinical depression is far too low nowadays. He calls depression a "catch-all" diagnosis driven by clever marketing. It’s normal to feel depressed at some stage in life, he says.

He notes that when the first anti-depressant was developed, its manufacturer, Geigy, thought that there would be too few patients to make it worthwhile. "Now, depression is all around, and antidepressant drugs have a dominant share of the drug market." The World Health Organisation even predicts that by 2020 depression will be the second biggest global burden of disease after chronic heart disease.

Professor Parker backs up his assertions with results from 242 teachers whom he has been studying since 1978. More than three- quarters of them met contemporary criteria for depression. This means, he says, that milder forms of depression are being pathologised.

His sparring partner, , of the University of Sydney, contends that lives of many people who might have otherwise committed suicide have been saved by a diagnosis of depression. And people nowadays no longer feel stigmatised if they are depressed. If depression can be identified in young people earlier, their problems might be resolved with psychological treatments rather than drugs.