Concordance between two personality disorder instruments with psychiatric inpatients

Area of Science:

• Psychiatry
• Psychological Assessment
• Clinical Psychology

Background:

• Accurate diagnosis of personality disorders is crucial for effective psychiatric treatment.
• Self-report inventories and structured interviews are common tools for personality disorder assessment.
• The Millon Clinical Multiaxial Inventory (MCMI-I) is a widely used self-report measure.

Purpose of the Study:

• To compare the diagnostic agreement between the Millon Clinical Multiaxial Inventory (MCMI-I) and the Structured Interview for DSM-III Personality (SIDP) for axis II diagnoses.
• To evaluate the MCMI-I's adequacy in identifying DSM-III personality disorders in a psychiatric inpatient population.

Main Methods:

• Eighty-two psychiatric inpatients were assessed using both the MCMI-I and the SIDP.
• Diagnostic concordance was analyzed across personality disorder categories and dimensional trait scores.
• Bayesian statistical methods were employed to confirm the findings.

Main Results:

• Poor concordance was observed between the MCMI-I and SIDP for most personality disorder categories.
• The exception was the borderline personality disorder category, which showed better agreement.
• Concordance for dimensional trait scores was also generally poor.

Conclusions:

• The findings question the adequacy of the MCMI-I as a sole instrument for diagnosing DSM-III personality disorders.
• Clinical interpretation of MCMI-I results for personality disorders should be done with caution.
• Further research may be needed to validate self-report measures against structured interviews for personality assessment.