The construct validity of the MMPI-2/MMPI-2-RF Restructured Clinical (RC) scales and the assessment of personality disorders

The current study examined the construct validity of the Restructured Clinical (RC) scales (Tellegen et al., 2003) of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) and MMPI-2-Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008) and the assessment of personality disorders. Tellegen et al. (2003) constructed the RC scales to address the perceived psychometric limitations of the Clinical scales and to measure the core psychological constructs of each of the Clinical scales whilst enhancing convergent and particularly discriminant validity. Tellegen et al.'s project resulted in the development of nine RC scales that were designed to be independent of the pervasive influence of the first factor, more distinctive and a more accurate measure of the core psychological constructs the original Clinical scales were designed to measure. This study utilised a forensic sample (n = 83) in order to analyse the construct validity of the RC scales when compared to the Structured Clinical Interview for the fourth edition of the DSM (DSM-IV; APA, 1994) Axis II Disorders-Personality Questionnaire (SCID-II PQ; First, Gibbon, Spitzer, Williams & Benjamin, 1997) and the Revised NEO Personality Inventory (NEO-PI-R; Costa & McCrae, 1992). The findings for this study demonstrated the construct validity of the RC scales when compared to the SCID-II PQ personality disorder raw scores and the NEO-PI-R domain and facet scales. The RC scales also accounted for additional variance over the NEO-PI-R domain scales for 8 out of the 10 SCID-II PQ personality disorder raw scores and provided a clinically accurate profile of personality disorders when expressed in their more pathological variants in a forensic population. The findings provide strong support for the construct validity of the MMPI-2/MMPI-2-RF RC scales and the assessment of personality disorders in a forensic setting. The results also support the aims of Tellegen et al. to create a set of scales that accurately measure the core psychological constructs of the Clinical scales whilst enhancing convergent and discriminant validity.