A combined factor analysis of the Millon Clinical Multiaxial Inventory and the MMPI in an offender population

The Millon Clinical Multiaxial Inventory (MCMI) is a recently introduced instrument designed to measure both symptomatology and long-standing patterns of personality disorder in clinical populations. Because it is designed to assess clients who are similar to those with whom the MMPI is often used (e.g., adjudicated offenders), a question may arise as to whether the two instruments measure the same aspects of clients' function. This study investigated this question by conducting a combined factor analysis of the two instruments in a criminal offender population (N = 2,245). Results indicated that although there are important areas of overlap between the two instruments, each also contains unique sources of variance. The results are interpreted as supporting the use of both instruments as part of an objective assessment battery, as has been suggested by several authors.