[Factorial dimensions of the Millon's MCMI-II in substance addicts]

The Millon Clinical Multiaxial Inventory II is a widely used questionnaire for the assessment of personality in clinical settings, especially in addictive behaviors. The aim of this study is to determine the underlying factorial structure of the MCMI-II in a sample of 1,106 drug-dependents who seek treatment. All participants completed the MCMI-II and the TCI-R. Multivariate exploratory factor analysis was performed. The results show that, in the MCMI-II, there is a main part that assesses symptoms of recent onset associated with the Axis I disorders, a scale that explores autolytic ideation, two scales that explore issues related to the use of alcohol and other drugs, two scales that assess normal personality traits, and seven scales that explore dysfunctional personality traits. Although the objective of the MCMI-II is the assessment of personality, the results indicate that the largest part of the questionnaire assesses not necessarily stable conditions and which have appeared recently. The scales measuring dysfunctional personality traits are combined to account for disorders without a clear match to the theory of reference. We conclude that, when using the MCMI-II with diagnostic purposes, one should consider the presence of unstable conditions that could artifactually increase the prevalence rates and the coexistence of personality disorders and addictive behaviors.