The untidy nature of mental health disorders and their diagnosis
By Liz Lockhart
Controversy over psychiatric diagnosis would now appear to be reaching fever pitch. Mental Healthy has already 
reported on arguments which are raging over the diagnosis of personality disorders and in particular antisocial personality disorder as well as autism. In the latest outburst depression and anxiety come under the spotlight.
The Diagnostic and Statistical Manual of Mental Disorders (DSM) is being revised for the first time since 1994, this will be the fifth change since the DSM was originally published by the American Psychiatric Association in 1952.
The proposed changes are causing much debate and concern along with much research. Moreover, there are bigger concerns over the validity of DSM as a whole. DSM is currently used for the formal diagnostic criteria for every psychiatric disorder.
‘Almost no one likes the DSM, but no one knows what to do about it,’ said Randolph Nesse, a psychiatrist from the University of Michigan. ‘A huge debate over when depression is abnormal seems likely to be resolved by removing the so-called ‘grief exclusion’. At the moment depression is not diagnosed in the two months after loss of a loved one.’
‘The result of this proposed change would be that people experiencing normal grief will receive a diagnosis of major depression. Doing this would increase consistency in diagnosing depression, but at the cost of common sense. It’s clear that bereavement is not a mental disorder,’ Nesse added.
Randolph Nesse and Dan Stein, a psychiatrist with University of Cape Town are the coo-authors of an article which is published in the current issue of BMC Medicine. The article outlines the difficulty of categorising mental disorders and the authors expect it to displease many of their colleagues.
‘The problem is not the DSM criteria. The problem is that the untidy nature of mental disorders is at odds with our wish for a neat, clean classification system,’ Ness said.
Just one example of the effort to define psychiatric disorders according to their causes and brain pathology is this proposed abolition of the grief exclusion in the diagnosis of major depression. The rest of medicine recognises many disorders that do not have specific causes, Nesse and Stein say.
Nesse added ‘Conditions such as congestive heart failure can have many causes. This doesn’t bother physicians because they understand what the heart is for, and how it works to circulate blood.’ He went on to point out that physicians recognise symptoms such as fever and pain are not diseases but useful responses.
‘These symptoms can be pathological when they’re expressed for no good reason, but before considering that possibility, physicians look carefully for some abnormality arousing such symptoms. Likewise, the utility of anxiety is recognised, but its disorders are defined by the number and intensity of symptoms, irrespective of the cause,’ Nesse said.
‘It’s vital to recognise that emotions serve functions in the same way that pain, cough and fever do, and that strong negative emotions can be normal responses to challenging or anxiety-provoking situations.’
Nesse urges his colleagues and concerned members of the public to have realistic expectations at this time that the DSM is, once more, revise.
‘Instead of specific diseases with specific causes, many mental problems are somewhat heterogeneous overlapping syndromes that can have multiple causes. Most are not distinct species like birds or flowers. They are more like different plant communities, each with a typical collection of species. Distinguishing tundra from alpine meadow, arboreal forest and Sonoran desert is useful, even though the categories are not entirely homogenous and distinct,’ Nesse concluded.
