An Australian psychiatrist has accused the medical profession of over-diagnosing depression, and says thousands of people are wrongly being prescribed drugs to treat it.
According to Professor Gordon Parker of the University of New South Wales, the current threshold for what is considered to be "clinical depression" is too low and he warns that the condition is becoming less credible.
Professor Parker says being blue at times is a normal part of the human condition and by medicalising normal human distress we are in danger of reducing the condition to the "absurd".
In a 15 year study Parker followed 242 teachers and found that 79 per cent of the respondents met the criteria at one time or another for the current present medical diagnosis for major, minor or very mild "subsyndromal" depression.
The first criteria required a person to be in a "dysphoric mood" which included feeling "down in the dumps" for two weeks; the second criteria involved appetite change, sleep disturbance, drop in libido and fatigue.
Professor Parker says it is normal to feel depressed and a low threshold for diagnosing clinical depression risks treating normal emotional states as illness.
He puts this over-diagnosis of clinical depression down to a change in its categorisation, in 1980, which saw the condition split into "major" and "minor" disorders.
He says while the simplicity and gravitas of "major depression" gave it credit with clinicians, its descriptive profile set a low threshold.
Clinical depression is often a case of the brain chemistry lacking serotonin production and the worry is that when a bad patch in life is overdiagnosed as clinical depression, the powerful drugs used to treat depression are being used to treat brains that are basically working as they should and there is no fault in the brain chemistry.
These powerful anti-depressants have a range of side-effects with 25% of patients experiencing problems stopping them; some research has found they can cause a rise in suicidal thoughts and actions and patients also report a loss of libido.
Professor Parker says anti-depressant drugs have cornered a large share of the drug market and they have been over- diagnosed because of the lack of a reliable diagnostic model along with exaggerated marketing claims by drug companies in a climate of heightened public expectations.