Overreport on the MCMI-III: concurrent validation with the MMPI-2 using a psychiatric inpatient sample

The MCMI-III (Millon, Davis, & Millon, 1997) is a widely used measure of personality often used in inpatient psychiatric settings. Although patients in such settings often overreport or exaggerate their symptoms, relatively little is known about how such a response set presents on the validity indexes of the MCMI-II. In this study, we used a sample of 191 psychiatric inpatients and compared MCMI-III modifier indices (Disclosure, Desirability, and Debasement) with the validity measures (L, F, Fb, F(p), K, and F - K) of the MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989). In addition, the MCMI-III Disclosure Index (Scale X, which imposes a set cutoff score for invalidity due to overreport) was compared to several cutoff scores on the validity scales of the MMPI-2. Although the MCMI-III indexes generally performed as expected, the MCMI-III had a very high tolerance for overreport. When contrasted with MMPI-2 F scale, the MCMI-II Disclosure Index (which gauges overreport) remained valid until scores on MMPI-2 F scale approached a T score of 120. In addition, the Disclosure Index was at the upper end or slightly exceeded the highest recommended cutoff scores on all other MMPI-2 validity scales except F - K. Clinicians using the MCMI-III alone are cautioned to consider the high tolerance the MCMI-III has for overreport.