The DSM-5 attempt to “dimensionalize” the diagnosis of personality disorder has worthy goals, but has suffered from grievously incompetent implementation. The work group has produced an ever-changing array of proposals, but each is a pastiche of complex and untested ratings that will most certainly never be used by clinicians. The fact that the proposals are universally condemned by researchers in the field has not prevented the work group from stubbornly soldiering on—seemingly oblivious to how impossibly cumbersome and out of touch are its proposals.
Mark Zimmerman, MD, of Brown University has accumulated a wonderful database for studying the diagnosis of personality disorders. He has systematically evaluated a grand total of 2150 psychiatric outpatients using carefully conducted semi-structured diagnostic interviews that assess DSM-IV personality disorders, their severity, and morbidity. Dr Zimmerman’s results (reported in the Journal of Clinical Psychiatry1) are a final nail in the coffin of the ill-fated DSM-5 dimensional proposals and usefully provide a viable alternative.
Dr Zimmerman performed a simple, but elegant and telling analysis. He treated the personality ratings of “not present,” “sub-threshold,” and “present” as a surrogate for a 3-point dimensional ratings. This is a crude, but extremely convenient and clinician friendly, method of converting personality disorder categories into personality dimensions. Zimmerman’s surprising and encouraging finding is that this makeshift dimensional method was able to save valuable information and worked reasonably well in predicting morbidity (better than categorical diagnosis and as well as 3-point, a 5-point, and criterion-count methods).
Zimmerman’s conclusions provide a clear way out of the DSM-5 personality disorders follies. “What we found is that the DSM-IV 3-point dimensional approach is an effective method in identifying personal disorders and these findings raise questions as to whether or not there is a need to modify the DSM-IV for personality disorders at all. We propose, instead, that we call more attention to the fact that there is a quasi-dimensional approach already built into the existing DSM-IV.”2
The DSM-5 personality disorders work group is a deer in headlights—unable to work its way out of the quagmire it has created for itself. The DSM-5 Task Force seems equally paralyzed. Zimmerman’s proposal is the only feasible solution—a practical, if imperfect, way to save dimensional personality diagnosis for DSM-5. The APA Trustees or Assembly should step in and provide the adult supervision needed to settle this issue in favor of the Zimmerman suggestion.
References:
1. Zimmerman M, Chelminski I, Young D, et al. Does DSM-IV already capture the dimensional nature of personality disorders? J Clin Psychiatry. 2011 Aug 23. [Epub ahead of print].
2. Looking Closely at Personality Disorders: Should DSM-5 Reduce and Redefine Them? Science Daily. http://www.sciencedaily.com/releases/2011/09/110921142211.htm. Accessed September 29, 2011.
