Are too many people now diagnosed as having depression? Two experts give their views in this week’s BMJ.

Professor Gordon Parker, a psychiatrist from Australia says the current threshold for what is considered to be ‘clinical depression’ is too low. He fears it could lead to a diagnosis of depression becoming less credible.

It is, he says, normal to be depressed and points to his own cohort study which followed 242 teachers. Fifteen years into the study, 79% of respondents had already met the symptom and duration criteria for major, minor or sub-syndromal depression.

He blames the over-diagnosis of clinical depression on a change in its categorisation, introduced in 1980. This saw the condition split into ‘major’ and ‘minor’ disorders. He says the simplicity and gravitas of ‘major depression’ gave it cachet with clinicians while its descriptive profile set a low threshold.

Criterion A required a person to be in a ‘dysphoric mood’ for two weeks which included feeling “down in the dumps”. Criterion B involved some level of appetite change, sleep disturbance, drop in libido and fatigue. This model was then extended to include what he describes as a seeming subliminal condition “sub-syndromal depression.”

He argues this categorisation means we have been reduced to the absurd. He says we risk medicalising normal human distress and viewing any expression of depression as necessary of treatment. He says:

“Depression will remain a non-specific ‘catch all’ diagnosis until common sense prevails.”

On the other side of the debate Professor Ian Hickie argues that if increased diagnosis and treatment has actually led to demonstrable benefits and is cost effective, then it is not yet being over diagnosed.

He says increased diagnosis and treatment has led to a reduction in suicides and increased productivity in the population. Furthermore the stigma of being ‘depressed’ has been reduced and the old demeaning labels of ‘stress’ and ‘nervous breakdown’ have been abandoned.

He says concerns about the number of new drug treatments on the market are unhelpful, arguing that new drugs to treat depression have reduced the prescribing of older, more dangerous sedatives and says that the consequences, such as suicide, of not being diagnosed or receiving treatment are rarely emphasised.

Audits carried out in the UK, Australia and New Zealand do not support the notion that the condition is over diagnosed, far from it, he says. Instead he points to the diagnosis rate of people with major depression and says this needs to be improved in which case rates of diagnosis must continue to rise.