Incremental validity of the MMPI-2 PSY-5 scales in assessing self-reported personality disorder criteria

The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Personality Psychopathology-Five (PSY-5) scales were developed to measure abnormal personality symptomatology. The present study examines the incremental validity of the PSY-5 scales beyond the clinical and content scales in assessing criteria associated with personality disorders. The current sample includes 240 male and 407 female clients from private practice settings who completed the MMPI-2 and the Multiaxial Diagnostic Inventory (MDI), a self-report checklist of Diagnostic and Statistical Manual of Mental Disorders (3rd ed, revised) symptoms. Six of the MDI personality disorder scales, conceptually related to the PSY-5 scales, are used as criteria. Hierarchical regression analyses determine the incremental validity of each PSY-5 scale. In most analyses, PSY-5 scales add a significant increment of variance to the clinical and content scales. Implications of the results are discussed.