MMPI critical item characteristics of the DSM-III borderline personality disorder.

This study attempted to distinguish the borderline personality disorder (BPD) from other personality disorders (OPD) on the basis of the Lachar and Wrobel critical item list. Seventy-five male psychiatric inpatients with diagnoses fitting DSM-III criteria for BPD and OPD and ranging in age from 24 to 47 years completed the MMPI. Lachar's critical item set, composed of 111 items taken from the MMPI, was then selected from each of the 75 subjects' response items. BPD and OPD patients significantly differed on only the Lachar Substance Abuse subscale. Implications of this study are discussed with regard to the concept that personality structure involves a continuum of psychopathology. The Lachar critical item list provided support for drug abuse as part of the diagnostic criteria for BPD and displayed promise for identifying areas of psychopathology on which treatment may be focused.