Development and validation of the Japanese version of the Mentalization Questionnaire (MZQ-J)

The aim of this study was to develop the Japanese version of the Mentalization Questionnaire (MZQ-J), used to measure mentalizing deficits, and to test its validity and reliability. The author conducted an Internet survey, and data for 250 adults were collected. A confirmatory factor analysis indicated that the MZQ-J had a single factor structure common to both genders, and sufficient internal consistency and test-retest reliability were confirmed. A correlation analysis showed that the MZQ-J was closely related to self-related mentalization as well as to mindfulness, empathy, Big Five personality traits, attachment, and self-esteem. The MZQ-J clearly showed correlations with pathological indicators of borderline personality traits and depression and anxiety. The results established the acceptable validity and reliability of the MZQ-J. The MZQ-J will also make it possible to provide appropriate clinical psychological assistance tailored to mentalizing capabilities and compare research findings of empirical studies regarding mentalizing at the international level.