The threshold for a diagnosis of depression is too low, leading to thousands of people being diagnosed with the condition when they are merely unhappy, according to a leading expert. But the suggestion has already been criticised from some quarters, in part due to concerns that a higher threshold would lead to more suicides.

In a ‘head-to-head’ in the 18 August edition of medical journal the BMJ Gordon Parker, of the University of New South Wales in Australia, argues that “current criteria are medicalising sadness”. He points out some of his research showing of 242 teachers 79 per cent met criteria for some kind of depression over 15 years (Scotsman). The Guardian notes that sales of antidepressants have increased massively in recent years – between 1998 and 2003 sales in Japan rose fivefold.

In response Ian Hickie, of the University of Sydney, argues people with depression are still missing out on treatment. Hickie’s view is backed by mental health charity SANE, with Marjorie Wallace, its chief executive, saying “[I]t is better to risk over diagnosis than to leave depression untreated. One in ten people with severe depression may take their own life.” (BBC and The Independent).

Their articles have lead to a series of messages to the BMJ’s online letters system from doctors across the world (responses to Parker, responses to Hickie). As psychiatrist Keith Dudleston, who works for a Community Mental Health Team in Devon in the UK, points out: “The interested educated observer of this controversy will be surprised that despite fifty years of intensive research, and the publication of at least two well used diagnostic manuals, two senior academic psychiatrists appear unable to agree upon the criteria for the diagnosis of one of the most common psychiatric conditions.”