Australia is responding to the complex challenge of overdiagnosis

To the Editor: I read with interest the article by Moynihan and colleagues1 and commend the authors on their timely review of this important topic. While the article referred to research that had highlighted concerns about overdiagnosis in relation to several medical and surgical conditions, the only psychiatric condition mentioned was attention deficit/hyperactivity disorder.

The authors referred to the problem of medicalisation as one of the possible drivers of overdiagnosis in one of the figures within the article, but not in the text of the article — medicalisation is the process by which non‐medical problems become defined and treated as disorders. In 2005, the medical expenditure on identified medicalised conditions in the United States was estimated to be about US$77 billion.2

Medicalisation in psychiatry has been a particular concern because of the problem created by ever‐expanding definitions of mental disorders and lowering of diagnostic thresholds.3 This has been well illustrated by the changes in the diagnostic criteria within the successive editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM) published by the American Psychiatric Association, now in its fifth edition (DSM‐5).

The effect of a change in the DSM diagnostic criteria was reported in 2001: changes from the third edition (DSM‐III) to the fourth edition (DSM‐IV), with an increase of the variety of stressors (events) considered capable of leading to post‐traumatic stress disorder (PTSD), led to a finding that 38% of DSM‐IV PTSD cases resulted from its wider definition.4 In the DSM‐5 the diagnostic criteria for PTSD have been further relaxed, so that “emotional reactions to the traumatic event” are no longer part of the diagnostic criteria.

Another example of overdiagnosis in psychiatry is that of adjustment disorder. A 2008 article stated that there are “huge [numbers] of false‐positives for depressive and anxiety disorders because the context of symptoms is not taken into account,” and that the diagnosis of adjustment disorder “seems, by definition, ideally suited to apply to healthy people in dangerous and uncertain circumstances”.5

It is to be hoped that the 7th international Preventing Overdiagnosis conference in 2019 will include a session on overdiagnosis also in psychiatry.