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Work on the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5)—scheduled to be published in May 2013—has been ongoing for more than a decade. Momentous advances in genetics and brain imaging since publication of DSM-IV in 1994 have generated optimism that an improved understanding of the neurobiologic underpinnings of psychiatric disorders might lead to a paradigm shift from the current descriptive classification system to a more scientific etiopathophysiological system similar to that used by other medical specialities.1
Some fear that any changes to our current classification system may be premature and could make an already complex system even more unwieldy.2 Scores of articles about the content and process of DSM-5 and several critiques and commentaries on the topic have been published. The American Psychiatric Association (APA) has made the DSM-5 process transparent by posting frequent updates to the DSM-5 Development Web site (www.dsm5.org), seeking feedback from the psychiatric community and the public, and presenting progress reports by members of the DSM-5 Task Force at scientific meetings.
There have been few discussions on the implications of DSM-5 from the practicing clinician’s vantage point, which I seek to present in this series of articles, the remainder of which will be published here, at CurrentPsychiatry.com. In this article, I:
- provide a brief history of psychiatric classification, focusing on the origins and evolution of the DSM system
- summarize the limitations of DSM-IV
- note the challenges and tensions in the construction of DSM-5
- review the DSM-5 process
- outline its current status
- discuss the organization and content of future articles in this series.
Although I am a member of the DSM-5 Psychotic Disorders Work Group, I am solely responsible for the content and any opinions that I offer in this article and series. All details of DSM-5 that I discuss are publicly available at www.dsm5.org. I’ve been a clinician and clinical researcher for >25 years, and my opinions are colored by the need for clarity, rigor, clinical relevance, and a disdain for overly speculative thinking.
Evolution of DSM
A nosological system (system of classification of disease) enables clinicians to provide specific treatments for medical causes of human disease and/or disability with precise and predictable effects and guide patients and families about the likely course and outcome. Such classification systems also are used by:
- researchers, to learn more about the nature of the conditions being classified and develop better treatments for them
- health care systems, to provide optimal health care and track its appropriate provision
- insurance companies, to provide appropriate reimbursement for health care
- health product developers, including pharmaceutical companies, to develop health care products and promote their appropriate utilization
- government agencies, to determine health priorities and apportionment of health care resources
- public health agencies, to track the distribution of health and disease in communities around the world.
An ideal classification system would meet all constituents’ needs while perfectly mapping natural disease entities with distinct etiology and pathophysiology (validity), consistently allow all users to reach the same diagnosis (reliability), and provide clinicians with clear guidance about treatment and likely course for each of the entities (utility), with the list of entities being mutually exclusive and collectively exhaustive (coverage).
The current nosological system for psychiatric disorders originated in the late 19th and early 20th centuries and culminated in the first edition of the Diagnostic and Statistical Manual of Mental Disorders3 released in 1952 and a section related to mental disorders (section V) in the sixth revision of the International Classification of Disease (ICD).4 Whereas DSM focuses exclusively on mental disorders, the ICD is a general medical classification system that began covering mental disorders with its sixth revision in 1949. In subsequent revisions (ICD-7 through -10 and DSM-II through -IV), substantial changes in diagnostic criteria have been made, although the systems’ basic structure has been retained. Table 1 describes major changes from DSM-I through DSM-IV-TR.3,5-9 DSM and ICD both are being revised; DSM-5 is scheduled to be released in 2013 and ICD-11 is to be finalized by 2016.
Conceptual development of DSM-I to DSM-IV-TR
|DSM-I (1952)3||Presumed etiology. 106 diagnoses|
|DSM-II (1968)5||Glossary definitions. 185 diagnoses|
|DSM-III (1980)6||Paradigm shift. Explicit criteria. Emphasis on reliability. 265 diagnoses|
|DSM-III-R (1987)7||Modest changes. Blunted hierarchies. Clarifications. 292 diagnoses|
|DSM-IV (1994)8||Modest changes. More blunted hierarchies. 361 diagnoses|
|DSM-IV-TR (2000)9||Only text revision. 361 diagnostic conditions|
What do clinicians need?
Similar to ICD-10, DSM-IV is marked by considerable complexity, variable validity, limited clinical and research utility, and problems of burgeoning comorbidity.10 Efforts to revise DSM seek to address these limitations. From a clinician’s perspective, the most challenging aspects of DSM-IV derive from its complexity—which makes clinical application difficult—and its limited clinical utility, which is exemplified by artificial comorbidity,11 frequent use of “not otherwise specified” (NOS), and relative treatment nonspecificity with reference to diagnosis.