Despite the critics, psychiatrists need guidelines like the DSM-5

Clinicians must use their judgement and look beyond the narrow debate about whether mental illnesses have a biological or psychosocial basis. crises_crs/Flickr

This weekend saw the release of the fifth edition of the American Psychiatric Association’s Diagnostic and Statistical Manual (DSM-5). The manual has been attracting controversy throughout its revision process, but critical voices reached fever pitch in the weeks leading up to its release.

Indeed, in the fortnight before its release, DSM-5 was panned by the director of the US National Institute of Mental Health (NIMH) as well as the British Psychological Society’s (BPS) division of clinical psychology. Interestingly, the criticisms were at odds with each other.

The NIMH wants psychiatry to focus on the biological bases of mental illness while the BPS opts for psychosocial therapy. It seems that the DSM would have been damned whichever way it opted to go.

NIHM director Dr Thomas R Insel accused the manual of lacking scientific rigour, announcing that he intended to:

reshape the direction of psychiatric research to focus on biology, genetics and neuroscience so that scientists can define disorders by their causes, rather than their symptoms.

Criticism from the BPS was not directed straight at DSM-5 but was “provocatively timed”, according to the Guardian, and questioned the benefits of the manual. Here the BPS' spokesperson said:

it was unhelpful to see mental health issues as illnesses with biological causes.

But what are clinicians like me to think when confronted by criticism from such respectable sources? We need a set of labels, updated routinely, as a shorthand for talking with colleagues. Patients and families expect a diagnosis. We need to justify funding for medication and hospital care. Even funders of talking therapies and social supports expect a label.

The truth is that making a diagnosis in health care is complex, and it is even more complex in psychiatry. Say someone reports a painful arm after a fall. This may indicate a broken bone. The clinical examination that follows is usually helpful in finding tenderness and sometimes deformity. And technology, in the form of X-ray, is commonly used to make a definitive diagnosis.

Now, imagine the difficulty of diagnosis where the bulk of the information is from a patient’s own report of symptoms that are not necessarily observable by the clinician. There’s no definitive X-ray or blood test to point you in the right direction.

Welcome to the world of clinical psychiatry where:

the boundaries between many disorder “categories” are more fluid over the life course than was previously understood, and many symptoms assigned to a single disorder may occur, at varying levels of severity, in many other disorders.

Psychiatrists regularly treat people who experience marked distress and loss of function caused by diseases or syndromes that have continued to evade definitive biological definition.

The early DSM editions were American modifications of the World Health Organization’s International Classification of Diseases (ICD) to give a “pure” mental disorders chapter. DSM-I and DSM-II were clumsy by today’s standards and labelled the world as it was without much help from research.

But the American Psychiatric Association (APA) followed ground-breaking work into the categorisation of psychiatric conditions of the 1970s with the third edition of the DSM in 1980. DSM-III made a “best guess” at an archipelago of diagnosis, where each island or illness was confirmed as discrete with borders separated by clear water. A revision to iron out inconsistencies followed in the form of DSM-III-R and DSM-IV was published in 1994.

By 2002, the APA was convinced that two decades of “modern” DSM categories had not generated valid, clearly separated diagnoses. Research, it seemed, had “not confirmed the wisdom of the current structure.” The islands tended to stick together and overlapped repeatedly. The map was a mess for researchers and clinicians alike.

In the latest edition of the manual, conditions will be clustered in chapters with dimensional measures encouraged over discrete diagnostic categories. If you can’t separate each island, drag them together and describe different bits as mountains or lagoons. This represents the triumph for supporters of a “spectrum of illness”.

The leaders of the process that changed the diagnostic concepts (driven by more than two decades of peer-reviewed scientific research) might have expected some public applause. Instead, even before the launch of the DSM-5, negative public comments criticised their work.

But the narrow debate that has ensued presumes mental illness has either a biological or psychosocial basis, which does no justice to our current scientific knowledge. Surely, in 2013, we can accept that all human memory, behaviour and emotion is connected to the chemistry of our brain.

But then many clinical psychologists spend all their time working with people who clearly have a biological basis to their problem, such as head injury or brain disease. Should we presume that the social circumstances or psychological make-up of these people never mix with their altered brain anatomy?

All of us are clearly a complex mixture of nature and nurture. Clinicians of all types, including psychologists, need to stay focused on the person in their office and use their judgement when making a diagnosis.

The previous edition of the DSM included a reminder to use diagnostic criteria as guidelines rather than a cookbook. Regardless of other changes, we can hope that this reminder is retained in the latest version lest any of us stray into using multiple unnecessary labels that distract from the distress of the person sitting in front of us.