In development for more than a decade, the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders  (DSM-5) is now a reality. The manual’s official release was announced at an early morning press conference on May 18, 2013, at the American Psychiatric Association’s Annual Meeting in San Francisco, California.
Revising psychiatry’s primary diagnostic resource takes work — years of planning, conducting field trials, revising, soliciting public feedback, revising again — and the effort has led to a revamped guide to psychiatric diagnosis. New diagnoses have been added, others amended or combined. Some originally proposed criteria drew so much public and professional controversy they were ultimately withdrawn from the final draft. But perhaps the most significant changes to the manual are conceptual: removing the multiaxial system, adding a dimensional diagnostic approach, and rearranging the chapter order and grouping of disorders.
The current 5-axial diagnostic system has been removed from DSM-5 in favor of nonaxial documentation of diagnosis. The new approach will combine the former axes I, II, and III with separate notations for psychosocial and contextual factors (formerly axis IV) and disability (formerly axis V). In addition to categorical diagnoses, a dimensional approach allows clinicians to rate disorders along a continuum of severity that will largely eliminate the need for “not otherwise specified (NOS)” conditions, now termed “not elsewhere defined” (NED)” conditions. The dimensional diagnostic system also better correlates with treatment planning.
Furthermore, the revised chapter order is intended to better reflect advances in the understanding of the underlying vulnerabilities of disease, as well as symptom characteristics of mental health disorders. Finally, diagnostic criteria for some disorders have been added or revised and are included in Section 2 of the manual, whereas those requiring further investigation are included in Section 3 (appendix).
Critics of DSM-5 have raised concern that it may be too early to create a new classification of psychiatric diseases. The main question is whether there have been sufficient advances in the pathophysiologic, phenomenologic, and therapeutic understanding of mental illness to warrant a revised DSM. Although the ultimate aim is to base diagnoses mostly on objective and, ideally, biologically measurable criteria, psychiatry is unfortunately still far from this goal.
This controversy has played out in initial comments by the director of the National Institute of Mental Health (NIMH), Thomas Insel, who urged for the development of a more biologically based nosology of mental disorders. In a blog post published on the NIMH Website, Dr. Insel pointed to the new NIMH Research Domain Criteria (RDoC) project as a possible replacement diagnostic tool sometime in the future, which will incorporate genetics, imaging, and other data into a new classification system and as “a first step towards precision medicine.” In a later joint statement by Dr. Insel and newly-appointed American Psychiatric Association president Jeffrey Lieberman, both commented that DSM and the International Classification of Diseases (ICD) “remain the contemporary consensus standard to how mental disorders are diagnosed and treated,” and that “what may be realistically feasible today for practitioners is no longer sufficient for researchers.” However, both also acknowledged that “looking forward, laying the groundwork for a future diagnostic system that more directly reflects modern brain science, will require openness to rethinking traditional categories. It is increasingly evident that mental illness will be best understood as disorders of brain structure and function that implicate specific domains of cognition, emotion, and behavior,” which is at the core of the RDoC initiative. These statements all converged in the belief that “DSM-5 and RDoC represent complementary, not competing, frameworks for this goal.”
In this context, the DSM-5 committee members have attempted a rational reexamination of the DSM-IV criteria on the basis of longitudinal research, incorporating data on the apparent relatedness of certain diagnoses with one another, including similarities in underlying vulnerabilities, symptom characteristics, and disease trajectories. Overall, most of the diagnoses and relevant criteria included in DSM-5 remain identical, or similar, to those in DSM-IV. However the updates are significant and represent a new diagnostic era in psychiatry.
What follows is a guide highlighting the major additions and revisions in the new DSM-5 edition.