SAN FRANCISCO -- Diagnosis of personality disorders would rely on a dimensional approach rather than on the conventional categorical approach under proposed revisions to the Diagnostic and Statistical Manual of Mental Disorders.
The new general criteria for personality disorders would rely on rating a patient's level of personality functioning plus either rating how well the patient matches one of five described personality types or performing a personality-trait assessment, Dr. Andrew E. Skodol said at the meeting.
The section on personality disorders is considered a "test case" for possible use of a dimensional approach to the diagnosis of all mental disorders eventually, said Dr. Skodol, chair of the DSM-5 Personality Disorders Work Group. "People who worked in the personality field had had discomfort with the categorical approach for decades and had been struggling with how to incorporate or integrate or replace categories with dimensions. We were a little bit ahead of the rest of the field."
Online posting of proposed revisions for the fifth Diagnostic and Statistical Manual of Mental Disorders (DSM-5) at www.dsm5.org in 2010 drew many comments and suggestions, some of which have been incorporated into the current proposal. Others did not shift the new model, such as an outcry about narcissistic personality disorder being represented as a trait instead of a type of disorder, according to Dr. Skodol, a research professor of psychiatry at the University of Arizona, Tucson.
The proposed DSM-5 defines a personality disorder as impairments in identity and sense of self, and in the capacity for effective interpersonal functioning. For diagnosis, the disorder must be manifested by a rating of mild impairment or greater in self- and interpersonal functioning on a 5-point "Levels of Personality Functioning" scale. In addition, the patient must be associated with a "good match" or "very good match" to a personality disorder type (antisocial/psychopathic, avoidant, borderline, obsessive-compulsive, or schizotypal), or must receive a rating of "extremely descriptive" when compared with one or more personality trait domains.
The personality must be relatively stable across time and consistent across situations, and must not be better understood as a norm within the patient's dominant culture or be attributable solely to the direct physiologic effects of a general medical condition or a drug or other substance.
The conventional categorical model of diagnosing personality disorders results in excessive diagnostic co-occurrence and heterogeneity, said Dr. Skodol, also of Columbia University, New York. There are 256 ways to meet criteria for borderline personality disorder in the DSM-IV, for example. Most patients who are diagnosed with personality disorder meet criteria for more than one personality disorder and, in some cases, for five or six personality disorders.
"That doesn't make a huge amount of sense," he said.
The DSM-IV sets "arbitrary" diagnostic thresholds, with no empirical rationale for a patient who meets four criteria for borderline personality disorder being considered normal while someone who meets five criteria gets the diagnosis, Dr. Skodol said. …