In the context of the sad suicides of a number of young people in Geelong, the well known psychologist, Dr Michael Carr-Gregg, has exaggerated the relationship between depression and suicide.

He goes so far as to claim that one girl’s death “is not about suicide. It is about depression.”

Although he presumably never examined her, Carr-Gregg tells us that “The internet did not kill her. Neither did cyber bullying. She was suffering from an illness and had it been diagnosed, she could have been treated.”

Carr-Gregg also perpetuates the discredited notion that depression is caused by a “chemical imbalance”, incorrectly claiming that “sometimes the biochemistry in their brain can go wrong and nothing anyone can say or do will alter that”.

But perhaps the most misleading of Carr-Gregg’s claims is that “undiagnosed and untreated depression” underlies 90 per cent of suicides. This claim ignores the fact that a minority of suicide victims are both diagnosed with depression and treated (almost always with antidepressants).

Furthermore, support for the relationship between depression and suicide comes mostly from psychological autopsy studies with problematic methodology.

Relatives, the primary source of information in such studies, often seek more socially acceptable explanations, and may be unaware of or unwilling to disclose certain problems, particularly those that generate shame.

Additionally, the presence of a psychiatric history would increase the likelihood of an ambiguous death being classified as suicide. Despite these biases, several psychological autopsy studies (here and here) have found rates of depression of only around one-third in suicides.

Carr-Gregg continues a strong tradition of denying the relevance of social factors (poverty, unemployment, racial discrimination, homophobia, internet bullying) in favour of tenuous and reductionist psychiatric explanations.

In order to reduce youth suicide, we need a population focus on addressing its social antecedents, not a clinical focus on diagnosing and treating individuals.

Jon Jureidini is a clinical associate professor in psychiatry at the University of Adelaide, and Melissa Raven is a lecturer in drugs and public health at Flinders University.