The unprecedented consultation by the fifth edition of the Diagnostic and Statistical Manual of Mental Health Disorders (DSM), due to appear in May 2013, shows that, following the trend of previous revisions, there are now more specific diagnoses and a number of refinements to previously defined disorders. Several of these are significant.

For example, the diagnostic term “intellectual disability” replaces the outdated term “mental retardation”. This broad category now includes new discrete diagnostic category of Autistic Spectrum Disorder (ASD). “Spectrum” is the operative word here, reflecting better the continuum of mild to severe autistic symptoms rather than distinct disorders.

The category “substance abuse and dependence” will be replaced by “addiction and related disorders”. Not only will this reflect drug and alcohol additions, but a new discrete category of “behavioral additions” is proposed in order to capture behaviors such pathological gambling (already present in DSM-IV and, perhaps in time and with greater empirical evidence, other behaviors such as “internet addiction”. This reflects growing empirical support in recent years that the same poorly regulated neurological and psychological reward systems involved in substance addiction are also implicated in addiction to particular behaviors.

Other proposed disorders include, for example, binge eating an ‘temper dysregulation with dysphoria”, alongside refinements to many existing diagnostic criteria. DSM-V will thus pathologize more behaviours. The total number of recognized disorders is likely to be well over 300.
However, as the numbers of recognized disorders increases the range of possible symptoms must be shared across these multiple disorders and, as such, it will be harder for clinicians to make a clean diagnosis. Many disorders share the same symptoms including, for example, anxiety, depressed mood or sleep problems. What this has meant in clinical practice, according to Darrel Regier and colleagues - key architects of the DSM-V - is a “remarkably high rate in speciality mental health settings of ‘not otherwise specified’ (NOS) diagnoses that do not quite fit the existing criteria”.

In an attempt to deal with this predicament, one of the most radical changes proposed for DSM-V is the addition of “dimensional assessments” to diagnostic evaluations of mental disorders. What this means is the assessment of a range of symptoms that are observed across multiple disorders.

While the identification of these common symptoms will not necessarily help clinicians reach cleaner diagnoses, it is hoped that they will help make better predictions about the development of disorders, inform the design and delivery of services and the assessment of outcome over time.

Thus, on one hand, the DSM will follow its predicted course: more and more behaviors will be medicalized thus further demarcating the lines of what is considered “normal” and “abnormal”. As warned by Til Wykes and Felicity Callard, the “pool or ‘normality’ [will] shrink to a mere puddle”. Yet, as the DSM behemoth advances, concerted efforts are being made to enhance its usefulness clinically and not only help practitioners name disorders, but also better understand the commonalities between them and thus inform intervention options.

References:
http://www.dsm5.org

Regier, Narrow, Kuhl & Kumpfer (2009). The conceptual development of DSM-V. American Journal of Psychiatry, 166, 6, 645 - 650.

Wykes & Callard (2010). Diagnosis, diagnosis, diagnosis: towards DSM-V. Journal of Mental Health, 19, 4, 301 - 304.