Dimensional representations of DSM-IV personality disorders: relationships to functional impairment.

OBJECTIVE This study compared three-dimensional representations of DSM-IV personality disorders and standard categories with respect to their associations with psychosocial functioning. METHOD Six hundred sixty-eight patients with semistructured interview diagnoses of schizotypal, borderline, avoidant, or obsessive-compulsive personality disorders or with major depressive disorder and no personality disorder completed questionnaires assessing three-factor and five-factor dimensional models of personality. Personality disorder categories, dimensional representations of the categories based on criteria counts, and three- and five-factor personality dimensions were compared on their relationships to impairment in seven domains of functioning, as measured by the Longitudinal Interval Follow-up Evaluation-Baseline Version. RESULTS Both the categorical and dimensional representations of DSM-IV personality disorders had stronger relationships to impairment in functioning in the domains of employment, social relationships with parents and friends, and global social adjustment and to DSM-IV axis V ratings than the three- and five-factor models. DSM-IV dimensions predicted functional impairment best of the four approaches. Although five-factor personality traits captured variance in functional impairment not predicted by DSM-IV personality disorder dimensions, the DSM-IV dimensions accounted for significantly more variance than the measures of personality. CONCLUSIONS Scores on dimensions of general personality functioning do not appear to be as strongly associated with functional impairment as the psychopathology of DSM personality disorder. A compromise in the ongoing debate over categories versus dimensions of personality disorder might be the dimensional rating of the criteria that comprise traditional categories.