Based on their study, the researchers believe these changes could result in false-negative diagnoses for patients. The paper is published in the
and is now available online in advance of print.
The DSM-5 Personality and Personality Disorders work group made several recommendations to change the approach toward diagnosing personality disorders. One of those recommendations is to delete five personality disorders as a way to reduce the level of comorbidity among the disorders. The ones originally slated to be removed include paranoid, schizoid, histrionic, narcissistic and dependent personality disorders. More recently, the Work Group recommended that narcissistic be retained. Lead author Mark Zimmerman, M.D., director of outpatient psychiatry at Rhode Island Hospital, points out, however, that no data were cited describing the impact this deletion had, or might have, on the overall prevalence of personality disorders. Likewise, no research was cited for the Work Group's reversal in deciding to retain narcissistic personality disorder.
"When it comes to revising the official diagnostic classification system, the guiding principle should be that criteria should not be changed in the absence of research demonstrating that the new approach is superior to the old in either validity or clinical utility, preferably both," Zimmerman states. "Despite assurances that only data-driven modification would be made, with each new edition of the DSM, we have witnessed repeated instances of changes being made in the absence of sufficient data demonstrating the new criteria is superior."
To evaluate the proposed changes of deleting five personality disorders from the DSM-5, Zimmerman and his colleagues evaluated 2,150 psychiatric outpatients, more than one-quarter of whom were diagnosed with one of the 10 DSM-IV personality disorders. When removing the proposed deleted disorders, 59 patients who were diagnosed with a personality disorder according to the DSM-IV criteria would no longer be so diagnosed. Thus, the findings suggest that patients will have false-negative diagnoses based on the proposed revisions to the DSM-IV.
Zimmerman comments, "The findings of the present study highlight our concerns about adopting changes in the diagnostic manual without adequate empirical evaluation beforehand. To be sure, there are problems with the classification of personality disorders, however, the identification of a problem is only the first step of a process resulting in a change to diagnostic criteria."
He concludes, "The classification of personality disorders would not be improved if the new criteria or diagnostic material were more clinically useful but less reliable and valid."