Predicting DSM-IV Cluster B personality disorder criteria from MMPI-2 and Rorschach data: A test of incremental validity

Despite their frequent conjoint clinical use, the incremental validity of R orschach (Rorschach, 1921/1942) and MMPI (Hathaway & McKinley, 1943) data h as not been adequately established, nor has any study to date explored the incremental validity of these tests for predicting Diagnostic and Statistic al Manual of Mental Disorders (4th ed. [DSM-IV]; American Psychiatric Assoc iation, 1995) personality disorders (PDs). In a reanalysis of existing data , we used select Rorschach variables and the MMPI PD scales to predict DSM- IV antisocial, borderline, histrionic, and narcissistic PD criteria in a sa mple of treatment-seeking outpatients. The correlational findings revealed a limited relation between Rorschach and MMPI-2 (Butcher, Dahlstrom, Graham , Tellegen, Sr. Kaemmer, 1989) variables, with only 5 of 30 correlations re aching significance (p < .05). Hierarchical regression analyses showed that both the MMPI and Rorschach data add incrementally in the prediction of DS M-IV borderline and narcissistic PD total criteria scores. The findings wer e less clear for the incremental value of Rorschach and MMPI-2 data in pred icting the total number of DSM-IV histrionic PD criteria, which were best p redicted by Rorschach data, and antisocial PD criteria, which were best pre dicted by MMPI-2 data. In addition to providing evidence of the incremental validity of Rorschach data, these findings also shed light on the psycholo gical characteristics of the DSM-IV Cluster B PDs.