The Diagnostic and Statistical Manual of Mental Disorders (DSM), whose development and forthcoming fifth edition we have looked at in Prevention Action in the last few days, is about diagnosing mental health disorders, yet prevention science is about getting intervening before impairments take root. Can we bridge the divide?

Since the current fourth edition of the DSM was written in 1994 there have been great advances in our understanding of who may be affected by mental health disorders and why and how. In laying out the research agenda for the next edition of the DSM, David Kumpfer, and colleagues, pay homage to the rapidly advancing fields of developmental neuroscience and genetic. “We now know much more”, they say “about how variations in brain functioning are related to disorders, coupled with the way in which a person’s environment and their genes interact to alter brain functioning”.

Yet despite these advances, developers of the DSM-V are forced to concede that this research is still very much in its infancy. According to Daniel Pine, chair of one of the task forces updating the DSM-V, and his colleagues, “much more information will be required before a complete diagnostic system based on brain structure and function can be implemented”.

So while neuroscience and genetics are likely to play a significant role in informing how we understand mental illness and how to intervene, the direct implications of this work for diagnosing and designing interventions efforts to prevent or treat mental illness are still to be realized.

Nonetheless, the proposed fifth edition of the DSM will be of use to prevention scientists and those concerned with designing services for children in at least three important ways.

First, the lines between normal and abnormal development are blurring. Growing evidence, reflected in the proposed fifth edition of the manual, indicates that many mental health disorders for example, hyperactivity and autism – often lie across a continuum with symptoms ranging in frequency and severity.

While it is the job of the DSM to draw a line indicating what is “normal” or “abnormal”, prevention science may intervene across the full continuum, intervening soon to tackle the early symptoms which may, if left unattended, develop into impairments.

The implications for those designing services to reduce the likelihood of impairments are to pay greater attention to the “normal” end of the spectrum. It follows that public health approaches to tackle mental health disorders - those interventions that seek to change the way entire populations think or behave - represent a vast well of largely untapped potential.

Second, there is a growing appreciation that many symptoms of mental health disorders span multiple diagnostic categories. Flattened mood, for example, is not only salient for those suffering with depression, but is also implicated in many other disorders, such as various forms of personality disorder and psychosis. It is, therefore, proposed in the fifth edition of the DSM for these cross-cutting symptoms play a greater role in diagnosis and be consistently assessed regardless of the specific disorder.

It follows that these cross-cutting symptoms, including anxiety, depression and anger, make strong candidates for prevention and early interventions. In addition to focusing directly on the treatment of the plethora of specific disorders, there is a strong argument for early intervention efforts to target those over-arching symptoms implicated in multiple mental health disorders.

The third way in which the DSM will prove of critical importance to prevention scientists is that there is more to mental health diagnoses than just symptoms alone; as described by Daniel Pine “work done in the past decade shows that for children, impairment is often as good a predictor of need for treatment and outcome of treatment as is the nature of symptoms or diagnosis”. It is thus proposed that the forthcoming fifth edition of the DSM places much greater emphasis on impairments to functioning rather than just the presence or absence of symptoms.

Reducing the impact of symptoms upon the lives of children and families, rather than just reducing the symptoms themselves may represent a radical shift in the focus of intervention efforts.

Prevention Action will report upon the final version of the DSM-V in 2013, alongside the updated World Health Organization diagnostic and classification system - the ICD-11, when they are published in 2013.

References:
http://www.dsm5.org

Pine and colleagues (2002). Advances in Developmental Science and DSM-V, in Kupfer and colleagues (Editors), A Research Agenda for DSM-V, Washington DC; American Psychiatric Association.